What is Hypoparathyroidism?
Hypoparathyroidism is a medical condition where the body secretes extremely low levels of parathyroid hormone (PTH). This is an uncommon condition. When the parathyroid glands do not secrete sufficient parathyroid hormone, it results in hypoparathyroidism. The human body consists of four parathyroid glands situated adjacent to the thyroid gland in the neck. Due to low production of PTH, there are abnormally low levels of calcium (hypocalcemia) in the bones and blood and increased levels of serum phosphorus (hyperphosphatemia).
Parathyroid hormone plays an important role in maintaining and regulating the balance of levels of two minerals in the body, namely phosphorus and calcium. In hypoparathyroidism the decreased production of PTH leads to extremely low ionized levels of calcium in the bones and blood; and an increased level of serum phosphorus.
Treatment of hypoparathyroidism comprises of supplements to help normalize the level of phosphorus and calcium. Depending on the cause of hypoparathyroidism, patient may need to take supplements for life.
Causes of Hypoparathyroidism
Acquired Hypoparathyroidism: This is the commonest cause of hypoparathyroidism, which occurs after removal of the parathyroid glands or accidental damage to them during surgery; which can be done as a treatment for thyroid gland disease, or for neck and throat cancer.
Hereditary Hypoparathyroidism: The parathyroid glands can be absent at birth, or they do not function properly. There are some types of hereditary hypoparathyroidism, which occur in relation to problems with other glands that produce hormones.
Autoimmune Disease: The body's immune system produces antibodies against the parathyroid tissues and mistakenly considers them as foreign bodies and rejects them resulting in the parathyroid glands stopping the production of PTH.
Decreased magnesium levels in the blood affect the function of parathyroid glands. It is important that the serum magnesium levels are at a normal level to maintain an optimum secretion of parathyroid hormone.
Extensive radiation therapy for cancer to the neck or face can cause destruction of the parathyroid glands and lead to hypoparathyroidism.
Risk Factors of Hypoparathyroidism
- Having a family history of hypoparathyroidism.
- Having a recent surgery of the neck, especially if the thyroid gland was involved.
- Having certain endocrine or autoimmune conditions, like Addison's disease.
Signs & Symptoms of Hypoparathyroidism
- Muscle cramps/aches in the feet, legs, face or abdomen.
- Burning or tingling sensation known as paresthesias in the fingertips, lips and toes.
- Twitching of the muscles or muscle spasms, especially around the mouth along with in the hands, throat and arms.
- Painful menstruation.
- Patchy hair loss including thinning of the eyebrows.
- Brittle nails.
- Coarse and dry skin.
- Mood swings and depression.
- Problems with memory.
- Serious symptoms which need immediate medical attention consist of seizures and difficulty in breathing. Both these are complications of hypoparathyroidism.
Complications of Hypoparathyroidism
Reversible complications occur from low levels of calcium and most of them will improve with treatment:
- Paresthesias are the sensation where the patient has sensory symptoms of pins and needles or odd, tingling sensations in the tongue, lips fingers and feet.
- Tetany is a condition where the patient has cramp-like spasms in the fingers and hands, which can be prolonged and painful. Patient can also have muscle twitches/discomfort along with spasms of the muscles of the throat, face or arms. When there are spasms in the throat, then patient can have difficulty in breathing, which is an emergency situation.
- Patient can lose consciousness and have grand mal seizures (convulsions).
- The kidney function can be impaired.
- There is malformation of the teeth, where the dental enamel and roots are affected.
- Patient can faint and have heart arrhythmias and even heart failure.
- Irreversible complications are those which can be prevented; however, once they occur will not improve with treatment:
- Mental retardation or slow mental development in children.
- Stunted growth (short stature).
- Deposits of calcium in the brain resulting in problems with balance and seizures.
Diagnosis of Hypoparathyroidism
Medical history of the patient is taken where the doctor asks the patient regarding his/her symptoms, such as tingling/muscle cramps in the lips, toes, fingers etc. The doctor will also want to know whether the patient has had any recent surgeries, which involve the neck or thyroid gland.
Physical exam of the patient is conducted where the doctor looks for signs which indicate hypoparathyroidism, such as twitching of the facial muscles.
Urine test is also done to assess whether the patient's body is excreting excessive calcium.
Developmental milestones and tooth development is checked in children.
Blood Tests are done and given below findings can indicate hypoparathyroidism:
- A low level of parathyroid hormone.
- A low level of blood-calcium.
- A high level of blood-phosphorus.
- A low level of blood-magnesium.
Treatment of Hypoparathyroidism
The aim of treatment for hypoparathyroidism is relieving the symptoms and normalizing the levels of phosphorus and calcium in the body. Hypoparathyroidism treatment usually consists of:
- Oral calcium carbonate supplements are given to increase the level of calcium in the blood. However, if they are given in high doses, then patient can sometimes experience gastrointestinal side effects, such as constipation.
- Vitamin D is given in high doses, commonly in the form of calcitriol to help the body in absorption of calcium and to eliminate phosphorus.
- Recombinant human parathyroid hormone (PTH) can also be beneficial according to some studies. It is currently being used for treating osteoporosis which is a bone-thinning disease. It has not yet been approved for treatment of hypoparathyroidism.
- Intravenous infusion of calcium is given after the patient has been hospitalized for immediate symptom relief. These IV infusions help in relieving severe muscle spasms seen with tetany. After discharge from the hospital, patient needs to continue to take oral calcium and vitamin D.
Dietary steps for Hypoparathyroidism comprise of taking the following diet:
- Diet rich in calcium, such as dairy products, broccoli, green leafy vegetables, kale, and fortified breakfast cereals and orange juice.
- Diet low in phosphorus-rich items, which means limiting the consumption of eggs and meats, avoiding carbonated soft drinks as they contain phosphorus.
Observation: Regular monitoring is needed where the doctor will check the patient's blood for monitoring the levels of phosphorus and calcium. Initially, these tests will be done weekly, then monthly. Over a period of time, blood tests will be done twice a year.
Diuretics: Despite treatment, if the patient continues to have low levels of calcium in the blood, then the doctor can prescribe a diuretic medication, specifically a thiazide diuretic such as metolazone or hydrochlorothiazide. Thiazides help in increasing blood-calcium levels whereas other types of diuretics, such as loop diuretics, decrease the level of calcium in the blood.
Regular Blood Tests: As hypoparathyroidism is a chronic (long-lasting) condition, treatment for this is usually lifelong along with performing regular blood tests for determining whether the calcium in at normal levels according to which dosage of the calcium supplements is adjusted.
Lifelong Treatment: Patients suffering from hypoparathyroidism can keep their symptoms under control with ongoing treatment. Early diagnosis and treatment of hypoparathyroidism helps in preventing the complications of this condition which can be potentially permanent.
Prevention of Hypoparathyroidism
There is no specific method for preventing hypoparathyroidism. However, if the patient is scheduled for a neck or thyroid surgery, then he/she should talk to the surgeon beforehand to assure that adequate measures are undertaken to avoid damage to the parathyroid glands during surgery. After any surgery on the neck or thyroid, patient should be on the lookout for signs and symptoms, which indicate hypoparathyroidism, such as a burning/tingling sensation in the lips, fingers, toes or cramping/ twitching of the muscles. If the patient starts to experience these symptoms, then prompt treatment should be started with calcium and vitamin D in order to decrease the effects of hypoparathyroidism.