• Approximately 20% of dialysis sessions are accompanied by muscle cramps1
  • Cramps are more pronounced in patients who require high ultrafiltration rates and are possibly dialyzed below their dry weight. They are presumably related to reduction in muscle perfusion that occurs in response to hypovolemia.  Compensatory vasoconstrictive responses may shunt blood centrally during treatment, and could play a role in promoting muscle cramps2.
  • Changes in intra or extracellular balance of potassium and concentration of ionized calcium can disturb neuromuscular transmission and produce cramps
  • Changes in serum osmolality and Na concentration during hemodialysis
  • Peripheral vascular disease, although common in dialysis patients, may not be associated with increased prevalence of intradialytic cramps which confirms that processes related to the dialytic treatment are responsible for the cramps3

Differential Diagnosis

While the majority of cramps are associated with dialysis treatment, the differential diagnosis is extensive and includes the following conditions:

  • Idiopathic cramps
  • Contractures (occurring in conditions such as metabolic myopathies, and thyroid disease)
  • Tetany (due to hypocalcemia or alkalosis)
  • Dystonias (occupational cramps, anti-psychotic medications)
  • Other leg problems such as restless leg syndromes and periodic leg movements, must be distinguished from cramps4

Treatment and Prevention

  • Many of the treatment strategies are similar to those used to treat intradialytic hypotension2
  • Physical maneuvers such as massage of the calf muscles and dorsiflexion of the foot are not very helpful2
  • Immediate treatment is to increase intravascular volume by interrupting or slowing ultrafiltration and administering saline, mannitol or glucose. In addition to affecting an intravascular shift of water, hypertonic solutions may directly improve blood flow to the muscles2
  • Use of dialysate sodium, potassium or calcium modeling may be helpful.  The concept of individualization of dialysate composition may be preventive2
  • Careful reassessment of the dry weight, counseling the patient to reduce interdialytic weight gain and using bicarbonate dialysis2
  • Carnitine,  quinine, prazocin, vitamin E, vitamin C and Japanese herbal extract have been tested with variable results5,6


  1. Wilkinson R, Barber SG, Robson V. Cramps, thirst and hypertension in hemodialysis patients — the influence of dialyzate sodium concentration. Clin Nephrol. 1977;7(3):101-105. Available from:
  2. Boudville N, Blake PG. Volume Status and Fluid Overload in Peritoneal Dialysis. In: Daugirdas JT, Blake PG, Ing TS, eds. Handbook of Dialysis. fifth. Philadelphia: Walters Kluwer Health; 2015:484-485.
  3. Brass EP, Adler S, Sietsema KE, Amato A, Esler A, Hiatt WR. Peripheral arterial disease is not associated with an increased prevalence of intradialytic cramps in patients on maintenance hemodialysis. Am J Nephrol. 2002;22(5-6):491-496. Available from:
  4. Riley JD, Antony SJ. Leg cramps: differential diagnosis and management. Am Fam Physician. 1995;52(6):1794-1798. Available from:
  5. Ahmad S. L-carnitine in dialysis patients. Semin Dial. 2001;14(3):209-217. Available from:
  6. Mandal AK, Abernathy T, Nelluri SN, Stitzel V. Is quinine effective and safe in leg cramps? J Clin Pharmacol. 1995;35(6):588-593. Available from:

P/N 103062-01 Rev A 03/2021