Foot-specific causes:

Ill-fitting shoes, including tight or high-heeled shoes, can contribute to muscle fatigue and tension. Other factors include muscle fatigue, mineral deficiencies, dehydration, certain medications, illnesses, and pregnancy [10] [11] [12].
Treating muscle tension:

If you experience tight leg muscles while sleeping, here are some treatments to consider:

Gentle massage:

Massage the affected leg to help relax the muscles.
Stretching:

Lengthen the leg muscles by extending the leg and bending the foot towards the body.
Walking in heels:

Walking on heels activates and relaxes the leg muscles.
Warm compresses:

Apply warm compresses using a heating pad or hot water bottle.
Over-the-counter pain relievers:

Take over-the-counter pain relievers, such as ibuprofen, when you feel pain.
Understanding the root causes and adopting appropriate treatments can significantly relieve leg cramps during sleep.