Kashif J. Piracha, MD, is a board-certified physician with over 14 years of experience treating patients in acute care hospitals and rehabilitation facilities.

Hemodialysis is a life-saving intervention when the kidneys are no longer functioning—but one that can cause significant side effects and complications. Many of the problems are related to the creation of dialysis access, through which blood is removed from the body and cleaned in a dialysis machine. Other complications are caused by the imbalance of fluids and electrolytes in the body and the impact this has on blood pressure and heart function.

Preventing complications of hemodialysis requires careful management on the part of your nephrologist (kidney specialist), the dialysis team, and you as the patient. Knowing the causes and symptoms can ensure that treatment is delivered quickly if a complication occurs, further extending your life, health, and well-being.

Hemodialysis is the most common form of dialysis in the United States. It involves removing blood from an access point in a vein, then cleaning the blood of toxins and excess fluids before returning it to the body.

Hemodialysis is meant to replicate the function of the kidneys, but it is an inexact science. If the speed of the procedure is too aggressive, or the individual being treated doesn't adhere to the proper dietary or fluid restrictions, the homeostasis (balance) of the body chemistry can be thrown off, causing side effects and complications.

The creation of an artificial access point in the body also poses a risk in that the closed vascular system is now open. Infection is the most common concern, but not the only one.

Here are just a few of the complications that a nephrologist will watch out for (and try to prevent) if you are on hemodialysis.

Hypotension is the medical term used to describe low blood pressure. This is a common occurrence during hemodialysis in which the dose and speed of the procedure can cause the too-rapid removal of fluids from the blood. By doing so, the internal pressure in the blood vessels will invariably drop, sometimes precipitously. This can cause symptoms such as:

A severe drop in blood pressure also increases the risk of blood clots. If left untreated, the formation of clots may require additional surgery to repair the access point and, in some cases, lead to stroke, seizures, and heart damage.

Adhering to the recommended fluid restrictions can help. By limiting your fluid intake, the amount being extracted during dialysis will be decreased, and any drop in blood pressure will be minimized.

Hemodialysis not only removes toxins and excess fluid from the body, but also many of the electrolytes that the body needs to function. In most cases, this won't pose a concern if you adhere to the proper diet.

However, if you have diabetes or take angiotensin-receptor blockers (ARBs), even adherence to the diet may not be enough to prevent a condition known as hypokalemia.

Hypokalemia is abnormally low potassium in the blood. Potassium is one of the most important electrolytes that the body uses to regulate fluid balance, muscle contractions, and nerve signals. When potassium levels drop excessively, it can affect all of these functions, causing:

If hypokalemia is extreme—defined as levels below 2.5 millimoles per liter (mmol/l)—it can cause potentially serious complications including the breakdown of muscle tissue, ileus (lazy bowels), cardiac arrhythmia (irregular heart rate), respiratory failure, paralysis, and atrial or ventricular fibrillation.

For most people, the risk of hypokalemia is low if they follow the prescribed diet and treatment plan. Even those at increased risk are unlikely to experience anything more than mild hypokalemia if they do.

Infection is an omnipresent risk in people undergoing hemodialysis. The creation of dialysis access provides bacteria and other microorganisms the opportunity to enter the bloodstream. If an infection were to occur, symptoms would typically include:

Antibiotics are typically used to treat the infection. Heparin, a type of blood thinner, may be used to prevent blood clots and limb ischemia. Maintaining optimal hygiene and sanitary practices can significantly reduce the risk of infection.

It is important to avoid bumping or knocking the dialysis access, since doing so can cause bleeding, especially if the graft or fistula is new. Bleeding increases the risk of infection, anemia, and vascular aneurysm (bulging of the arterial wall).

Fluid overload, also known as hypervolemia, occurs when the kidneys are no longer able to remove enough fluid from the body. If the dialysis machine is not calibrated correctly, hypervolemia may persist despite treatment.

Adhering to fluid restrictions and tracking your fluid intake can significantly reduce the risk of hypervolemia.

If overload persists despite fluid restriction (or develops soon after hemodialysis), let your nephrologist know so that adjustments to your treatment plan can be made.

If left untreated, hypervolemia can lead to heart problems, including congestive heart failure, cardiac arrhythmia, and cardiomegaly (enlargement of the heart).

Dialysis disequilibrium syndrome (DDS) is an uncommon neurological condition that typically affects people who have just started hemodialysis. It is believed to be the body's response to a procedure it considers abnormal, resulting in the release of inflammatory cytokines and other inflammatory chemicals that cause the brain to swell (cerebral edema).

This is usually a short-lasting complication that will resolve as the body adapts to treatment. Intravenous saline is sometimes used to raise blood pressure along with an injection of mannitol (a diuretic) to relieve swelling and pressure around the brain.

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Vadakedath S, Kandi V. Dialysis: A review of the mechanisms underlying complications in the management of chronic renal failure. Cureus. 2017;9(8):e1603. doi:10.7759/cureus.1603

Morfin JA, Fluck RJ, Weinhandl ED, Kansal S, McCullough PA, Komenda P. Intensive hemodialysis and treatment complications and tolerability. Am J Kidney Dis. 2016;68(5S1):S43-S50. doi:10.1053/j.ajkd.2016.05.021

National Heart, Lung, and Blood Institute. Low blood pressure.

Guttee V, Nie YX, Wang YM, Ding XQ. Impact of abnormal serum electrolyte levels and acid-base disorders on clinical outcomes among maintenance hemodialysis patients. Open Access Library Journal. 2017;4:e3623. doi:0.4236/oalib.1103623

Elliott TL, Braun M. Electrolytes: Potassium disorders. FP Essent. 2017;459:21-28.

Centers for Disease Control and Prevention. Know the signs and symptoms of infection.

Antlanger M, Hecking M, Haidinger M, et al. Fluid overload in hemodialysis patients: a cross-sectional study to determine its association with cardiac biomarkers and nutritional status. BMC Nephrol. 2013;14:266. doi:10.1186/1471-2369-14-266

National Kidney Foundation. Fluid overload in a dialysis patient.

Mistry K. Dialysis disequilibrium syndrome prevention and management. Int J Nephrol Renovasc Dis. 2019;12:69-77. doi:10.2147/IJNRD.S165925

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