If left untreated, thyroid could lead to severe muscle disease

Contributed by Dr.Abhijit Bhograj, Consultant Endocrinologist, Columbia Asia Hospital Hebbal

Our body is made up of a complex and numerous set of organs, muscles, tissues, and glands that help us function. The outer appearance might look simple but below the skin, there is a lot that is going on and a
lot that needs careful attention. It is not enough to look fine for a healthy body but to also ensure the proper functioning of the internal parts of our body which are controlled my multiple chemical messengers called hormones.
 
For instance, the thyroid gland which is a tiny butterfly gland in our necks might not be felt or thought about unless an abnormality occurs with it or it becomes dysfunctional. However, this little gland holds a
huge significance as it is responsible for making hormones that control your metabolism. The hormones released by the body, thyroid hormones, hence control the way the body makes use of energy, so they affect almost every organ in your body and contribute in almost every other function in the body, be it related to the brain, the muscles or digestion. Any irregularity with the thyroid can lead to various health problems in the longer run. 
 
Thyroid problems have multiple forms too. When the thyroid hormone is not enough in our body, it causes a condition called hypothyroidism or low thyroid which makes one’s system slow down. While when the thyroid is overactive and produces more thyroid hormones than the requirement of the body,
it is referred to be a case of hyperthyroidism. Either of the forms, if left untreated, can impact the muscles. 
Myopathy or muscle disease can occur as a result of hypothyroidism (hypothyroid myopathy) as well as hyperthyroidism (hyperthyroid myopathy). Thyroid-related myopathy can be severe and debilitating but can also be treated if handled timely on a mild stage.
 
Hypothyroid Myopathy
 
The exact cause is still unclear but experts do speculate the deficiency of thyroxine (T4) seen in
hypothyroidism leads to abnormal oxidative metabolism, which causes muscle injury and impaired
muscle function.
 
Some of the symptoms include:
 In the case of hypothyroid myopathy, general weakness is experienced by the person especially in the muscles closest to the centre of their bodies, such as the thigh or shoulder. This tends to cause problems climbing stairs or combing your hair.
 Apart from muscle symptoms, an increased creatinine kinase (CK) level could also be observed.
Creatinine kinase is a muscle enzyme that increases with a muscle injury.
 In rare scenarios, hypothyroidism can also lead to more severe muscle symptoms and can experience enlarged muscles, significant muscle stiffness, weakness, and pain.
 If not treated properly, combined with vigorous exercise and cholesterol-lowering medication, it could also result in rapid muscle breakdown.
 
In the case of hypothyroid myopathy, the thyroid hormone replacement medication can usually help in improving the muscle symptoms like cramps and stiffness but this improvement also takes time. When it comes to muscle weakness, it generally takes months altogether to resolve. Hence the early the
treatment, the faster the cure.
Hyperthyroid Myopathy 
When it comes to myopathy in hyperthyroidism, it’s likely that the elevated level of thyroid hormones in the body directly impacts the muscles. High thyroid hormone levels may lead to increased muscle
protein degradation and muscle energy use.
Some of the common symptoms in case of hyperthyroid myopathy are:
 Irregular muscle cramps and pain
 The weakening of the muscles. This may create difficulty for the person in climbing stairs, rising from a chair, holding or gripping objects, and even in reaching their arms above their head.
 In some rare cases, in myopathy from hyperthyroidism, the muscles that are affected can even include those that help you swallow and breathe.
 Muscle wasting
In the case of hyperthyroid myopathy, treating hyperthyroidism can cure muscle disease as well.
However, it takes a very long time even after the thyroid is brought back to normal. Hence it becomes crucial to not leave your thyroid untreated for a long time.
 
Muscle complaints are not uncommon in thyroid diseases. However, if they are left untreated and the thyroid is not timely and appropriately addressed, it can generally be alleviated with simple remedies.