When muscles invade your nights
Unlike restless legs syndrome , which causes tingling and constant restlessness, nocturnal cramps are sudden, localized, and very painful . They occur without warning, most often in the calf, and then disappear, leaving residual tension that can ruin the rest of the night.
Who is most affected?
Some people are particularly susceptible to this type of spasm:
Pregnant women : especially in the last trimester, due to hormonal and circulatory changes.
For athletes : overly intense training or insufficient recovery increases the risk.
After 50 : the progressive loss of muscle mass makes the fibers more sensitive.
In case of dehydration : a deficit in water and electrolytes disrupts the contraction/relaxation balance.
The often-overlooked causes of nighttime cramps
Several factors could be at play behind these painful contractions:
A mineral deficiency : magnesium, potassium and calcium are essential for muscle relaxation.
A bad sleeping posture : sleeping on your stomach or with your feet stretched out shortens the calf and promotes tightness.

Slowed blood circulation : when lying down, venous return in the legs is less efficient.
Certain medications , such as antihypertensives, cholesterol treatments, or psychotropic drugs, can have this type of side effect.