What are nocturnal leg cramps?
Nocturnal leg cramps are pains that occur in your legs at night. They usually wake you from sleep, but you can also cramp while you're awake at night during periods of inactivity. These cramps usually happen in your calf muscles, less often in your thighs or feet. Nocturnal leg cramps are quite painful and cause the affected muscles to feel tight or knotted. Symptoms may last from several seconds up to several minutes. Your muscles be sore after the cramp goes away.
Who gets nocturnal leg cramps?
Although anyone can get nocturnal leg cramps, the number of people who get them increases with age. Slightly more women than men experience these leg cramps.
Nocturnal leg cramps have been reported by:
- 50 to 60% of adults
- 7% of children and teens
- 40% of pregnant women
Some 20% of patients who experience nocturnal leg cramps on a daily basis go to a healthcare provider for help.
Are nocturnal leg cramps the same as restless legs syndrome?
No. While both types of leg disturbances tend to happen at night, or at rest, restless leg syndrome does not cause severe, cramping pain. While restless legs syndrome can be painful, it's more of a discomfort or a crawling sensation that makes you feel the need to move your legs. As you move the restlessness is relieved, but discomfort returns when movement stops. With nocturnal leg cramps, the tightened muscle needs to be actively stretched out for relief.
What causes nocturnal leg cramps?
There's no sure cause of nocturnal leg cramps, but some cases have been linked to:
- Sitting for long periods of time.
- Over-exertion of the muscles.
- Standing or working on concrete floors.
- Sitting improperly.
Nocturnal leg cramps have also been linked to certain medical conditions and medications. These include:
- Narrowing of the arteries/circulation-related diseases.
- Narrowing of the spinal canal in the lower back (lumbar canal stenosis), which can compress nerves that travel from lower back to legs.
- Cirrhosis of the liver (scarring of the liver) due to alcoholism, hepatitis, or other causes.
- Dehydration/electrolyte imbalances.
- Parkinson’s disease.
- Nerve damage from cancer treatment.
- Kidney failure/hemodialysis.
- Peripheral neuropathy.
- Neuromuscular disorders (neuropathy, myopathy, motor neuron disease).
- Structural disorders (flat feet).
- Endocrine disorders (diabetes, hypothyroidism).
- Medications: IV iron sucrose, conjugated estrogens, raloxifene (Evista®), naproxen (Naprosyn®), teriparatide (Forteo®).