Tight Calves and Night Cramps

You’re asleep and suddenly your calf seizes into a hard, agonising knot (something that I unfortunately experienced…multiple times. Not fun.).

You’re out of bed hopping, foot flexed, waiting for it to pass. Afterwards the muscle stays sore for a day or two.

Night cramps are common, harmless in most cases, and there are things that genuinely help.

Stop one as it happens

1. Straighten the leg and pull your toes towards your shin. Use a hand, or a towel looped round the foot. Stretching the cramping muscle is what stops it.
2. Or stand up and put weight through the foot, heel down.
3. Then massage and warm it. This is where a heat pad earns its place: 15 minutes on the calf afterwards, lowest setting, eases the residual tightness and the soreness the next day. A ball can help too: muscle knots, heat and a massage ball.

Warmth before bed may also reduce how often they happen for some people, though the evidence for that is anecdotal rather than strong. See warmth before bed, and note the pad goes off before you sleep: sleeping with a heating pad.

Reducing how often they come

• Stretch the calves before bed. Wall stretch, 30 seconds each side, knee straight then slightly bent. This is the measure with the most support behind it. Tight hamstrings and a stiff Achilles often come as a set.
• Keep the bedding loose at the foot end, so your toes aren’t held pointed all night.
• Stay hydrated, particularly in Singapore’s heat and if you’ve exercised.
• Build up exercise gradually. Cramps often follow an unaccustomed jump in activity. See DOMS: heat or ice?
• Review your medication with a doctor or pharmacist. Some medicines, including certain diuretics and statins, are associated with cramps.
• In pregnancy, night cramps are common in the later months. See pregnancy back and pelvic pain for what’s safe.

On supplements: magnesium is widely recommended for night cramps, and the evidence in older adults is weak. It may be worth a try if your doctor agrees, but don’t expect much, and don’t start it if you have kidney problems without asking first.

The one thing to rule out first

A cramp is not the same as a swollen, warm, tender calf.

If one calf is swollen, warm, tender to squeeze, or the skin is red, that can be a blood clot (DVT). Heat and massage are the wrong response and can be dangerous. See a doctor the same day, particularly after a long flight, surgery, a period of bed rest, or in pregnancy.

Call 995 if that leg symptom comes with breathlessness or chest pain.

A genuine cramp grips and releases within minutes and leaves a sore but normal-looking calf. Swelling that persists is a different problem. Prominent, aching veins are their own case: varicose veins and heat.

See a doctor if…

• Cramps are frequent enough to disturb your sleep regularly
• You also have numbness, weakness or pins and needles in the leg
• You get calf pain when walking that stops when you rest, which can indicate poor circulation
• You have diabetes, kidney disease or thyroid problems. With diabetes, keep heat off the lower legs and feet entirely.
• Cramps started after a new medication
• Your urine turned dark after intense exercise with severe muscle pain. That’s urgent; see sore after the gym.

Clinically reviewed by: Nigel Chua (Hand Occupational Therapist) & Louise Yow (Physiotherapist). This article is general information, not a diagnosis. electricheatpad.com sells electric heat pads.