Hello, Thanks for your query. The Cramps are caused by hyper excitability of the nerves that stimulate the muscles. Cramps at rest are very common, especially in older adults, but may be experienced at any age, including childhood. Rest cramps often occur during the night. While not life threatening, night cramps (commonly known as nocturnal cramps) can be painful, disruptive of sleep, and they can recur frequently (that is, many times a night, and/or many nights each week). Thyroid can cause severe cramps in legs and foot. Most cramps can be stopped if the muscle can be stretched. For many cramps of the feet and legs, this stretching can often be accomplished by standing up and walking around. Gently massaging the muscle will often help it to relax, as will applying warmth from a heating pad or hot soak. I do hope that you have found something helpful and I will be glad to answer any further query. Take care