There are different possible causes for the symptoms that you are experiencing. One of the potential causes is hypothyroidism
which is a low level of thyroid hormone. It is diagnosed by a examination (there are certain features that are present when a person with hypothyroidism is examined) and by a blood test
to assess the level of the thyroid hormone.
In addition to hypothyroidism, electrolyte imbalance
(levels checked by blood tests) and excess activity can result in muscle spasms and pain.
I do hope that you have found something helpful and I will be glad to answer any further query.