Hi.
There is nothing serious. Cramps are caused due to the following reasons:
Straining or overusing a muscle. ...
Compression of your nerves, from problems such as a spinal cord injury or a pinched nerve in the neck or back.
Dehydration.
Low levels of
electrolytes such as magnesium, potassium, or
calcium.
Not enough blood getting to your muscles.
Next Steps
Hot compression and ice compression before sleep would help. If this still continues, Consult a General physician.