Symptom guide
Why do I get charley horses at night?
A charley horse is the everyday name for a sudden, involuntary, painful contraction of a muscle — most often the calf, most often between midnight and 4am. It is one of the most common reasons adults wake in pain, and it is rarely dangerous. Understanding the mechanism is what makes the difference between guessing and acting.
Review status: Written by the CalfCramp.com editorial team from published clinical literature. Independent medical review is pending — this page has not yet been reviewed or approved by a licensed clinician, and it is educational content, not medical advice.
What is actually happening in the muscle
During a nocturnal cramp the calf muscle fires far faster than it does during voluntary effort, and it keeps firing after you would normally have stopped. Electromyography studies of cramping muscles show very high discharge rates, which points to the nerve supplying the muscle rather than the muscle tissue itself as the origin of most cramps.
The leading explanation in the current literature is altered motor-neuron excitability: when a muscle sits shortened for a long period, the feedback that normally quiets the motor neuron is reduced, and the neuron becomes easier to trigger. Sleep provides exactly those conditions — hours of a shortened calf with the foot pointed.
- The pain outlasts the spasm because the muscle has contracted through its full range against no load
- Tenderness the next day is normal after a strong cramp and does not mean injury
- Cramps typically last seconds to a couple of minutes but can recur in clusters the same night
Who tends to get them
Prevalence rises with age; a large share of adults over 60 report night cramps at least occasionally. Pregnancy, long periods of standing, heavy training loads, dehydration, and certain medications also appear repeatedly in the literature as associations.
Association is not the same as cause. Most people with night cramps have no underlying disease at all, which is why a structured self-care routine helps so many of them.
What tends to change the odds
The interventions with the most consistent support are mechanical rather than nutritional: regular calf and hamstring stretching, avoiding sustained plantarflexion in bed, keeping bedding loose, and building tolerance gradually if you have increased activity.
- Nightly calf and hamstring stretching before bed
- Sleeping with the foot in a neutral position rather than pointed
- Loose bedding so the sheet does not hold the foot pointed
- Reviewing medications with a clinician if cramps started after a prescription change
Want the whole routine in one place?
The Nocturnal Calf Cramp Protocol collects the evening sequence, the in-the-moment response, a two-week tracking log and the questions to bring to a clinician into a single guide you can follow tonight.
This page is educational and is not medical advice, diagnosis, or treatment. Persistent, worsening, or one-sided calf symptoms belong with a licensed physician before starting any new routine.
Questions people ask
Information on CalfCramp.com is educational only and does not constitute medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition or before changing anything about your care.