Muscle cramps are strong and painful that happens when there is a sudden involuntary contraction of one or more muscles of the body. Muscle cramps are harmless but cause a great deal of discomfort for the time when one is suffering from them.

Causes and reasons for muscle cramps can be many. It usually happens when one muscle is overused over a period of time or when that muscle has been holding one position for a prolonged period.

Exercising
Many people face muscle pain after exercising or at night on days they have exercised. When a muscle is used a lot in an activity, it leads to cramps.
Walking
For most people, walking continuously for long periods or even walking in breaks but walking long distance over all causes muscle cramps. In some cases, walking on concrete surfaces also leads to muscle cramps in the legs.
Running
If you are not used to running but run once in a while, you are likely to suffer from muscle cramps especially in the legs and thigh area.
Not warming up before exercising
Warm up is important before any kind of physical activity, be it a run, yoga, normal work out, or lifting weights. Warming up means getting your body prepared for the unusual physical activities. Missing warm ups can cause severe pain in the muscles. No warm ups before heavy weights work out or push up and pull ups can lead to muscle cramps and pain for days.
Weakness
Most people can go through heavy physical activities without any muscle cramps because of a strong immune system. General weakness can cause muscle cramps too.
Age
Older people are more prone to muscle cramps as people start getting weak as they age.
Lack of proper diet
Our body needs to have a strong immune system to fight all kinds of illnesses. When there is a deficiency of potassium, calcium, and other essential minerals in the blood, it leads to muscle cramps.
Dehydration
Lack of water intake leads to dehydration that later cause many problems in the body including muscle cramps.

Treatments that cure muscle cramps
You can try resting to cure muscle cramps. Improve your diet and drink plenty of water to make your body and immune system strong so it can fight common illnesses and problems like muscle cramps.
Avoid junk food as it takes away essential nutrients from your body and causes you muscle cramps and other illnesses.
Warm up before any rigorous exercise will help you avoid muscle cramps later on.