If you’ve ever woken up yelling because your calf suddenly knotted, that was a leg cramp. The NHS says leg cramps are common, usually harmless, and only last a short time. They can last from a few seconds to 10 minutes, and most people get them at night or when resting. During a cramp, stretching and massaging the muscle, or standing up and putting your weight on that leg, may help. For prevention it describes a wall calf stretch done 3 times a day, the last just before bed. This sets out the NHS page “Leg cramps”.
1. During a cramp: stretch, massage, stand and put weight on the leg. Painkillers take too long to help during it, the page says.
2. Wall calf stretch: hold 2 or 3 seconds, repeat for 5 minutes, 3 times a day. The last one just before bed.
3. See a GP if cramps disturb your sleep, come with numbness or swelling, or last over 10 minutes.
What they are and how long they last — NHS
The NHS describes a leg cramp as a muscle in the leg tightening and causing a sudden pain that can make it hard to move. Cramps can last from a few seconds to 10 minutes, and afterwards the muscle might feel sore for up to 24 hours. They can happen at any time, but most people get them at night or when resting. Contrary to the image of cramping mid-workout, this page says rest is the more common time.
During a cramp — NHS
- Stretch and massage the muscle — this may ease the pain during a cramp
- Stand up and put your weight on the leg with the cramp, which may also help
- Paracetamol or ibuprofen are for soreness after the cramp — during it they take too long to work to help
Prevention — the wall calf stretch (NHS)
Regular calf stretching may help reduce cramps but may not stop them completely, the NHS says, and it gives the steps.
| Step | What the NHS says | Worth noting (our gloss) |
|---|---|---|
| 1 | Face a wall and stretch out your arms until your hands can just touch it | Distance sets the intensity |
| 2 | Stand up straight with your feet flat on the floor | Keep the heels down |
| 3 | Lean forward, pressing your hands against the wall until you feel your calves stretch; hold for 2 or 3 seconds | — |
| 4 | Stand up straight again | — |
| 5 | Repeat a few times for 5 minutes, 3 times a day (the last just before bed) | 15 minutes a day in total (our sum) |
Putting the last session just before bed fits the point that cramps mostly come at night (our reading). Stretching after exercise in general is in stretching after exercise, and swollen legs in leg swelling stretches.
Why they happen — NHS
The NHS lists six causes: ageing; putting too much strain on muscles during exercise, which can be worse in hot or humid weather; pregnancy, usually in the later stage; certain medicines such as statins for cholesterol or diuretics for high blood pressure; not drinking enough fluids (dehydration); and liver disease from drinking too much alcohol. It adds that the reason for some cramps is unknown.
Fluids are covered in daily water intake and alcohol in alcohol units. Even if a medicine may be the cause, don’t stop it on your own — the NHS constipation and heartburn pages say not to stop prescribed medicine without advice (constipation). If you take several medicines, see medicines for older adults too.
When to see a GP, and what happens — NHS
| When | What the NHS says | Worth noting (our gloss) |
|---|---|---|
| Cramps disturb your sleep | See a GP | — |
| Also numbness or swelling in your legs | See a GP | — |
| Cramps last longer than 10 minutes | See a GP | Past the usual range |
A GP will examine you to find the cause and suggest treatment accordingly. Stretching comes first; if exercise hasn’t helped, quinine tablets may be offered, but quinine is not suitable for everyone, so the GP will discuss the risks and side effects.
Checklist
- ☐ During a cramp: stretch, massage, stand and put weight on the leg
- ☐ Wall stretch: 2 or 3 seconds, for 5 minutes, 3 times a day, last before bed
- ☐ Don’t overdo exercise on hot, humid days; drink enough
- ☐ Disturbed sleep, numbness or swelling, or over 10 minutes: see a GP
Questions that remain
Does magnesium stop cramps?
The NHS leg cramps page we read doesn’t cover magnesium. Supplements in general are in magnesium supplements.
What about bananas?
This page says nothing about food, so we haven’t either.
Sources
- NHS — Leg cramps — source (page shows: reviewed 1 December 2023, next review 1 December 2026; checked 12 October 2026). A few seconds to 10 minutes, soreness up to 24 hours, at night or resting, stretch, massage and stand, painkillers afterwards, 5-step wall stretch, 6 causes, 3 GP reasons, quinine.
- Not read. Korean agency guidance on muscle cramps; evidence on magnesium and cramps.
- What we added. The “worth noting” column and the 15-minute daily sum.
Where else to check
- A pharmacist — your medicines and cramps.
Written on 12 October 2026. The content is from the NHS; the glosses are ours.
