How is hypoparathyroidism diagnosed?
Hypoparathyroidism is usually diagnosed via a simple calcium blood test. In hypoparathyroidism, your blood calcium level is low, your blood phosphate level is high, and your parathyroid hormone level is low.
Further blood tests may then be carried out to confirm this diagnosis such as :
- thyroid function
- kidney function
- bone profile
- vitamin D levels
A bone scan and a kidney scan should be requested at the first appointment
A 24 hour urine test shoud be ordered regularly. You will be given a container in which to collect your urine over a 24 hour period. This needs planning!
There are a number of things that your doctor may look for if hypoparathyroidism is suspected:
- Your doctor may tap in front of your ear with your mouth slightly open. If your calcium levels are low because of hypoparathyroidism, this can cause repeated twitching of the muscles in your face. This is called Chvostek’s sign.
- Your doctor may also inflate a blood pressure cuff around the lower part of your arm. If your calcium levels are low because of hypoparathyroidism, this can lead to carpopedal spasm. This may be painful so don’t allow this check to be done unless really necessary. You are not a guinea pig!
- Your eyes may be checked for cataracts which can be a complication of hypoparathyroidism.
- Your muscle reflexes may be checked. This is a painless examination done by tapping the tendons of the muscles, for example, at the knee or the elbow. It is done using a special instrument called a tendon hammer. If your calcium levels are low due to hypoparathyroidism, these reflexes can be much more forceful than normal.
Genetic conditions can’t be prevented but genetic testing is available in centres around the UK. Genetic counselling aims to help parents understand how the condition may affect their family and enable them to make informed decisions.
Other possible investigations
Your doctor may suggest some other tests to look for the cause of your hypoparathyroidism, for example:
- Hand x-rays – to look for the shortened bones seen in pseudohypoparathyroidism.
- Echocardiogram (an ultrasound scan of the heart) – to look for heart abnormalities associated with DiGeorge syndrome.
- Genetic studies – special blood tests can be performed if your doctor suspects that you have an inherited cause for your hypoparathyroidism.
- If your doctor suspects that your hypoparathyroidism is caused by an autoimmune process, they may suggest some other blood tests. For example, they may want to look at your thyroid gland to check that this is not also affected.