Words you hear every session —
finally explained.

How blood is removed from your body and returned during treatment. Your access is the connection point between you and the dialysis machine. There are three main types: a fistula (a surgically joined vein and artery in your arm), a graft (a synthetic tube connecting a vein and artery), or a catheter (a tube placed in a large vein in your chest, neck, or groin). Fistulas are generally considered the preferred long-term access type.

A measure of how effectively your dialysis treatment is removing waste from your blood. Your care team uses a calculation called Kt/V to measure adequacy. The goal is typically a Kt/V of 1.4 or higher per session. If your adequacy is low, it may mean your sessions need to be longer, your blood flow rate needs adjustment, or other changes are needed.

A protein made by your liver that is measured in your monthly labs. Low albumin is associated with poor nutrition and worse outcomes in dialysis patients. A normal albumin level for dialysis patients is generally considered 4.0 g/dL or higher. If yours is trending down, a conversation with your care team and possibly a dietitian is worthwhile.

A condition in which your blood does not have enough healthy red blood cells to carry adequate oxygen to your tissues. Anemia is extremely common in dialysis patients because failing kidneys do not produce enough erythropoietin (EPO), the hormone that signals red blood cell production. Anemia contributes significantly to fatigue. It is treated with medications called ESAs (erythropoiesis-stimulating agents) and sometimes iron.

A surgically created connection between an artery and a vein, usually in your forearm or upper arm. Over time, blood flowing through the fistula causes the vein to enlarge and thicken making it suitable for repeated needle placement during dialysis. AV fistulas are the preferred long-term access type because they have lower complication rates than grafts or catheters.

Measurable substances in your blood that your care team monitors to assess your health and treatment effectiveness. Common biomarkers in dialysis include potassium, phosphorus, hemoglobin, albumin, calcium, BUN (blood urea nitrogen), creatinine, and PTH. These numbers tell a story about how well your body is managing dialysis. You have the right to receive and understand your results.

The force of blood against your artery walls. Measured as two numbers systolic (the top number, pressure when your heart beats) and diastolic (the bottom number, pressure between beats). Blood pressure management is central to dialysis care. Both high and low blood pressure during treatment are common and have clinical implications. Your BP is measured before, during, and after every session.

A waste product from protein breakdown that builds up in your blood when kidneys are not working. Your BUN is measured before and after dialysis sessions as part of calculating your treatment adequacy (Kt/V). High pre-treatment BUN means your kidneys produced a lot of waste since your last session. This number alone does not tell the whole story it is interpreted alongside other values.

The process of inserting needles into your access site at the start of each dialysis session. Two needles are typically used one to remove blood and one to return it. Cannulation requires skill and experience, particularly for fistula access. You have the right to request an experienced technician if you have concerns about who is placing your needles.

A tube placed into a large vein (typically in the neck, chest, or groin) used for dialysis access when a fistula or graft is not yet available or usable. Catheters have higher infection risk than fistulas and are generally considered a temporary solution. If you have been on a catheter for a long time, it may be worth asking your care team about access planning.

How effectively dialysis treatment removes waste products from your blood. Clearance is the core goal of dialysis — replacing what your kidneys cannot do on their own. Your care team measures clearance using Kt/V. Low clearance over time can affect how you feel and your long-term health. Adequate clearance requires sufficient treatment time and appropriate blood flow rates.

Painful involuntary muscle contractions that commonly occur during dialysis, most often in the legs, feet, or hands. Cramping is common but not something you simply have to endure silently. It is often related to fluid removal rate, dry weight accuracy, or electrolyte changes during treatment. Telling your care team specifically when and how severely you cramp gives them information to work with.

A waste product produced by muscle activity that is filtered from the blood by working kidneys. In kidney failure, creatinine builds up. In dialysis patients, creatinine is measured in labs and used as one indicator of kidney function and dialysis effectiveness. Unlike in people with working kidneys, high creatinine in dialysis patients is expected — what matters is the pattern over time.

A machine used in peritoneal dialysis (PD) — a different type of dialysis that uses the lining of the abdomen rather than a machine to filter blood. Hemodialysis and peritoneal dialysis are two different treatment modalities. If you are in a hemodialysis center, your treatment uses the hemodialysis machine, not a cycler. Some patients transition between modalities over time.

The specially formulated fluid that runs on the other side of the dialyzer membrane during your treatment. Waste products from your blood move across the membrane into the dialysate, which is then discarded. The specific composition of dialysate its concentrations of sodium, potassium, calcium, and bicarbonate can be adjusted for individual patients and can affect how you feel during treatment.

The component of the dialysis machine that actually filters your blood. The dialyzer contains thousands of tiny hollow fibers through which your blood flows. Waste products pass from the blood through the fiber walls into the surrounding dialysate. Think of the dialyzer as the functional heart of your treatment. Dialyzers come in different sizes and types, which can be matched to individual patient needs.

Your target weight after all excess fluid has been removed during dialysis. It represents what your body would weigh if your kidneys were removing fluid normally. Dry weight is one of the most important numbers in dialysis and you have the right to know yours. It should be reassessed when you gain or lose actual body weight not just fluid.

In peritoneal dialysis, dwell time is the period during which dialysate fluid remains in the abdomen performing waste exchange. In hemodialysis, the equivalent concept is treatment time how long your blood is being actively processed. Treatment time in hemodialysis directly affects how much waste is cleared and is a prescribed part of your treatment plan.

Swelling caused by excess fluid accumulating in body tissues. In dialysis patients, edema commonly occurs in the legs, ankles, feet, and sometimes around the eyes. Significant edema before a treatment session means your body has accumulated more fluid than ideal. Persistent edema that does not fully resolve with treatment may indicate your dry weight needs adjustment.

Hormones or hormone-like medications that stimulate your bone marrow to produce red blood cells. Healthy kidneys produce erythropoietin naturally. When kidneys fail, EPO production drops and anemia results. ESA medications given during dialysis replace what your kidneys can no longer make. Common examples include epoetin alfa and darbepoetin. Your hemoglobin level determines your dose.

The medical term for permanent kidney failure severe enough to require dialysis or transplantation to survive. ESRD does not mean the end of your life it means the beginning of a managed treatment pathway. People live for many years on dialysis. The term is used in insurance coverage, Medicare eligibility, and clinical documentation.

A surgically created connection between an artery and a vein that is used for dialysis access. The connection causes the vein to enlarge and strengthen over time, creating a durable site for needle placement. Fistulas generally last longer and have fewer complications than grafts or catheters. A fistula must be allowed to mature (usually 3-6 months) before it can be used for dialysis.

The daily limit on fluid intake recommended for dialysis patients to prevent excessive fluid accumulation between sessions. Most dialysis patients have a fluid restriction because the kidneys can no longer regulate fluid balance independently. Your specific limit depends on your residual urine output and your dialysis prescription. All liquids count including ice, soup, gelatin, and high-water-content foods.

A characteristic of dialyzer membranes describing how easily water and larger molecules can pass through. High-flux dialyzers are more permeable and can remove larger waste molecules that standard (low-flux) membranes cannot. Many centers now use high-flux dialyzers as the standard of care. You can ask your care team which type of dialyzer is used in your treatment.

The protein in red blood cells that carries oxygen throughout your body. Low hemoglobin means your blood is carrying less oxygen which directly contributes to fatigue and reduced exercise tolerance. In dialysis patients, the target hemoglobin range is typically 10-11.5 g/dL. Your hemoglobin is monitored regularly and ESA medications are adjusted accordingly.

A medication given during dialysis to prevent blood from clotting in the dialyzer and tubing. Heparin is a standard part of most hemodialysis treatments. Some patients who are at higher risk for bleeding receive reduced-dose or heparin-free dialysis. If you have had recent surgery or other bleeding risks, your care team should know and adjust accordingly.

A drop in blood pressure during or after dialysis. Intradialytic hypotension (IDH) is the most common serious complication of hemodialysis. Symptoms include dizziness, weakness, nausea, sweating, and feeling faint. If you experience these symptoms during treatment, alert your nurse immediately do not wait to see if they pass. Repeated episodes of IDH are associated with worse long-term outcomes.

Elevated blood pressure. Most dialysis patients have hypertension because failing kidneys cannot regulate blood pressure normally. Fluid overload carrying too much fluid between sessions is a major contributor to high blood pressure in dialysis patients. Many patients find their blood pressure improves significantly when they stay closer to their fluid restriction and dry weight target.

When a dialysis needle punctures through the wall of a fistula or graft vein, causing blood or fluid to leak into surrounding tissue. Infiltration causes swelling, hardness, bruising, and sometimes significant pain at the access site. If you notice swelling or hardness around your needle sites during treatment, tell your nurse immediately. Catching infiltration quickly reduces damage to your access.

The weight you gain between dialysis sessions due to fluid accumulation. After a three-day gap (typically over the weekend), you will naturally gain more fluid than after a two-day gap. This difference is expected and your care team should account for it. Consistently gaining significantly more than your recommended allowance places extra strain on your heart and makes treatment more difficult.

Iron is essential for red blood cell production. Many dialysis patients are iron deficient because iron is lost through the dialysis process and through blood remaining in the dialyzer. Low iron makes anemia worse and ESA medications less effective. Iron is often given intravenously during dialysis sessions. Your ferritin (stored iron) and TSAT (transferrin saturation) levels are monitored in your labs.

The standard measurement of dialysis adequacy how much waste was cleared from your blood relative to your body size during a session. K = clearance rate of the dialyzer, t = treatment time, V = volume of body water. The target Kt/V for hemodialysis patients is typically 1.4 or higher per session. Consistently low Kt/V may mean you need longer sessions or other adjustments. You can ask for your number at any appointment.

A mineral that affects how your heart and muscles work. High potassium (hyperkalemia) is a serious risk for dialysis patients because the kidneys normally regulate potassium balance. Very high potassium can cause dangerous heart rhythm problems. Your potassium is measured monthly in your labs and you may be advised to limit high-potassium foods like bananas, oranges, potatoes, and tomatoes.

Regular bloodwork used to monitor your kidney function, nutrition, anemia, and dialysis adequacy. Dialysis patients typically have comprehensive labs drawn monthly. Your labs tell your care team how well treatment is working and whether adjustments are needed. You have the right to receive your lab results and to have them explained to you. Asking for your results is appropriate and encouraged.

A type of synthetic vascular graft used for dialysis access, shaped in a loop under the skin often in the forearm or upper arm to connect an artery and vein. Grafts can be used sooner after surgery than fistulas because they do not require the same maturation period. However, grafts are more prone to infection and clotting than native fistulas.

The type of dialysis treatment you receive. The main modalities are in-center hemodialysis (most common), home hemodialysis, and peritoneal dialysis (PD). Each modality has different requirements, schedules, and lifestyle implications. If you have not had a conversation with your care team about whether your current modality is the best fit for your life situation, that conversation is worth initiating.

The semi-permeable barrier inside the dialyzer through which waste products pass from your blood into the dialysate. The characteristics of the membrane determine what kinds of molecules can be removed — smaller molecules cross easily, while larger ones require high-flux membranes or different treatment approaches. Different membrane materials may be more or less compatible with individual patients.

A physician who specializes in kidney disease and its treatment. Your nephrologist oversees your dialysis prescription, reviews your labs, and manages the medical aspects of your kidney care. You should be seeing your nephrologist regularly. If you have questions about your overall care direction, treatment adequacy, or access to transplant evaluation, your nephrologist is the appropriate person to ask.

A clinical term used when a patient does not follow prescribed treatment missing sessions, leaving early, or not following dietary or fluid guidelines. The word compliance has a power imbalance built into it that many patient advocates object to. If you are struggling to adhere to your treatment plan for any reason practical, emotional, or otherwise telling your care team is the most important step toward finding a workable path forward.

A mineral found in many foods that your kidneys normally filter from the blood. In kidney failure, phosphorus builds up. High phosphorus (hyperphosphatemia) over time damages blood vessels and bones — it is one of the more serious long-term complications of dialysis. Most patients take phosphate binders with meals to reduce how much phosphorus is absorbed from food. Foods high in phosphorus include dairy, nuts, beans, and many processed foods.

A hormone that regulates calcium and phosphorus balance. In dialysis patients, PTH is often elevated because the parathyroid glands respond to low calcium and high phosphorus by producing more hormone. Chronically elevated PTH causes bone disease and other complications — a condition called renal osteodystrophy. PTH is monitored regularly and treated with medications that manage calcium, phosphorus, and vitamin D levels.

The process of preparing the dialysis machine and circuit before your treatment begins filling the lines and dialyzer with saline to remove air and prepare the system. Priming is part of the setup process your care team completes before each session. If you notice the machine is not being set up correctly or a step seems to be skipped, it is appropriate to ask.

The pressure readings on your dialysis machine during treatment. Arterial pressure measures the pressure at which blood is leaving your body; venous pressure measures the pressure as blood is returned. Abnormal pressure readings can indicate problems with your access or blood flow — such as a clot, kink, or needle position issue. Alarms during treatment that trigger pressure readings are normal and should prompt your care team to check the circuit.

At the end of your treatment session, saline is used to push the blood remaining in the machine's tubing and dialyzer back into your body. Rinse back adds approximately 0.3-0.5 kg of fluid which is factored into your post-treatment weight and fluid calculations. Not all centers perform full rinse back practices vary.

Any remaining kidney function that continues after dialysis has started. Even small amounts of residual function contribute meaningfully to overall clearance, fluid balance, and patient wellbeing. Preserving residual kidney function for as long as possible is a clinical goal in dialysis care. Certain medications, particularly NSAIDs and some antibiotics, can damage residual function and should be used with caution.

The practice of cleaning and reprocessing a dialyzer for use by the same patient across multiple sessions. Reuse was once common but is now less prevalent. If your center reuses dialyzers, they are cleaned between your sessions and tested for performance before being used again. Each dialyzer is labeled with the patient's name and only reused for that specific patient.

A sterile saltwater solution used in dialysis for priming the machine, treating low blood pressure during treatment (saline bolus), and rinsing blood back into your body at the end of sessions. When your blood pressure drops during treatment, your nurse may give you a saline bolus — a small amount of saline pushed quickly into your blood return line to raise pressure. This adds fluid temporarily but is sometimes necessary.

Pre-written instructions in your medical chart that guide how your routine dialysis sessions are conducted including blood flow rate, dialysate composition, treatment duration, heparin dosing, and how staff should respond to common events like blood pressure drops. Your standing orders are your personalized treatment protocol. You are entitled to know what your standing orders say and to ask questions about them.

A narrowing of a blood vessel in or near your dialysis access that restricts blood flow. Stenosis in a fistula or graft can reduce blood flow rates during treatment, lower treatment adequacy, and eventually lead to access failure if not treated. Warning signs include high venous pressures, reduced blood flow during treatment, or changes in how your access sounds or feels. Stenosis is usually treated with balloon angioplasty.

One complete dialysis treatment from when your needles are placed and treatment begins until your needles are removed and you are disconnected from the machine. Your session duration is part of your dialysis prescription and is determined by your nephrologist based on your individual needs. Consistently leaving early or having sessions start late affects your total treatment delivery.

Sensations that indicate a working fistula. A thrill is the vibration you can feel when you place your fingers gently over a functioning fistula. A bruit is the sound (like a swishing or humming) you hear when a stethoscope is placed over the fistula. Every fistula patient should know how to check their thrill. If you cannot feel your thrill, especially after a treatment, contact your care center immediately it may indicate a clot.

A surgical procedure in which a healthy kidney from a donor (living or deceased) is placed into a patient with kidney failure. A successful kidney transplant is considered the optimal treatment for most patients with ESRD — offering better quality of life and longer survival than dialysis for many patients. Being evaluated for transplant, being listed, and staying active on the list all require patient advocacy and follow-through.

A lab value that measures how much of your transferrin (the protein that carries iron in your blood) is actually carrying iron. TSAT is used alongside ferritin to assess iron status in dialysis patients. A TSAT below 20% typically indicates iron deficiency that may need treatment. Iron deficiency worsens anemia and reduces the effectiveness of ESA medications.

The process of removing excess fluid from your blood during dialysis. The machine creates a pressure gradient across the dialyzer membrane that pulls water from your blood. The amount of fluid that needs to be removed depends on how much you have accumulated since your last session — which is why staying within your fluid limits matters. High ultrafiltration rates are associated with cramping, blood pressure drops, and cardiovascular stress.

The rate at which fluid is being removed from your blood during treatment, measured in milliliters per hour. Research has linked high UFR rates (above 10-13 mL/kg/hour) with increased cardiovascular risk and worse outcomes. UFR is determined by how much fluid you need to lose divided by your treatment time. Staying closer to your fluid limit between sessions directly lowers your UFR and makes treatment more tolerable.

The buildup of waste products in the blood due to kidney failure. Uremic symptoms include fatigue, nausea, loss of appetite, confusion, itching, and a metallic taste in the mouth. Dialysis treats uremia by removing these waste products. If you are experiencing significant uremic symptoms between sessions, it may indicate your dialysis prescription needs adjustment or that sessions are not adequately clearing waste.

The means by which your blood is accessed for dialysis encompassing fistulas, grafts, and catheters. Vascular access is often called the lifeline of dialysis because without functioning access, treatment cannot occur. Access problems clotting, stenosis, infection, and failure are among the most common reasons for dialysis patients to need emergency care or hospitalization.

The pressure reading on your dialysis machine as blood is returned to your body through the venous needle. Consistently high venous pressure can indicate a problem with your access — such as stenosis, a clot near the return needle, or poor needle positioning. Machine alarms triggered by venous pressure should always prompt your care team to investigate the cause.

Your weight is measured before and after every dialysis session. Pre-treatment weight tells your care team how much fluid to remove. Post-treatment weight confirms whether the target dry weight was reached. The difference between your pre and post weight is the amount of fluid removed. Understanding your own weight numbers helps you participate actively in your treatment planning.

How dialysis affects your overall physical and emotional functioning, your ability to work, your relationships, and your sense of control over your life. Quality of life in dialysis is a legitimate clinical concern — not just a personal one. If dialysis is significantly affecting your functioning or emotional health, that is a conversation worth having with your nephrologist, social worker, and care team. You do not have to simply endure.