Sleep and CKD

Poor sleep in CKD is multifactorial. Uraemic toxins affect neurotransmitter balance in the brain, altering the sleep-wake cycle. High phosphate and calcium disturbances cause restless legs syndrome and muscle cramps. Fluid overload leads to nocturnal breathlessness and frequent urination. Many CKD medications (steroids, some blood pressure tablets, phosphate binders) can disrupt sleep. Anxiety about health, depression, and the practical disruption of dialysis schedules (especially nocturnal haemodialysis or early-morning shifts) all compound the problem. Even before dialysis, sleep quality is measurably worse than in healthy controls.

Restless legs syndrome (RLS) is one of the most distressing sleep disorders in CKD. It typically begins in the evening, peaks at night, and is relieved only by moving the legs. The cause in CKD is not fully understood but is strongly associated with iron deficiency (even when blood haemoglobin is normal), high phosphate, and high PTH. RLS is also linked to peripheral neuropathy from diabetes or uraemia. Treatment starts with correcting iron stores — oral iron if ferritin is low, or IV iron in dialysis patients. Phosphate binders and dietary phosphate restriction help. If symptoms persist, dopamine agonists (pramipexole, ropinirole), gabapentin or pregabalin may be prescribed. Avoid caffeine and alcohol in the evening as they worsen RLS.

Obstructive sleep apnoea (OSA) causes repeated collapse of the upper airway during sleep, leading to oxygen desaturation, arousals and poor sleep architecture. In CKD, OSA is more common because of fluid redistribution (leg fluid moves to the neck when lying down), obesity, and autonomic dysfunction. OSA increases blood pressure, heart strain and stroke risk — already elevated in CKD. Symptoms include loud snoring, witnessed apnoeas, morning headaches, dry mouth and severe daytime sleepiness. Diagnosis requires a sleep study. Treatment with CPAP improves sleep quality, lowers blood pressure and may reduce cardiovascular events. Weight loss, avoiding alcohol before bed, and side-sleeping can also help.

Nocturia (waking to urinate) is common in CKD even before fluid restriction is needed. Reduced concentrating ability means the kidneys produce urine evenly throughout the day and night. In advanced CKD and on dialysis, fluid restriction is often prescribed, but fluid shifts still cause nighttime urination. Practical tips: limit fluid intake 2–3 hours before bed; avoid caffeine and alcohol in the evening; take afternoon dialysis diuretics earlier if possible; elevate legs for an hour in the late afternoon to mobilise fluid before lying down; and review medication timing with your team.

Good sleep hygiene is the foundation of better rest. Go to bed and wake up at the same time every day, even on weekends. Keep the bedroom cool (16–18°C), dark and quiet. Use the bed only for sleep and intimacy — not for watching TV or working. If you cannot sleep after 20 minutes, get up and do something relaxing in dim light, then return to bed. Avoid screens for an hour before bed (blue light suppresses melatonin). A warm bath or shower 1–2 hours before bed can help — the subsequent drop in body temperature promotes sleepiness. Light exercise during the day improves sleep, but avoid vigorous activity within 3 hours of bedtime.

If sleep problems persist despite good sleep hygiene, speak to your renal team or GP. Melatonin may help some people with CKD, though evidence is limited — it should be used under medical supervision because melatonin is metabolised by the kidneys. For insomnia, cognitive behavioural therapy for insomnia (CBT-I) is the first-line treatment and is more effective long-term than sleeping tablets. For RLS, iron studies and phosphate control are the first steps. For suspected OSA, ask for a referral to a sleep clinic. Do not self-medicate with over-the-counter sleep aids, herbal sedatives or antihistamines — these can interact with CKD medications and may not be safe with reduced kidney function.