What is hypoparathyroidism?
The parathyroid glands are four tiny glands located close to the thyroid gland in the neck that secrete the parathyroid hormone for controlling and maintaining the calcium and phosphorous levels in the body. Hypoparathyroidism is marked by inadequate levels of parathormone production by the parathyroid glands. This results in reduced levels of calcium in the blood (hypocalcaemia) and increased levels of serum phosphorous (hyperphosphataemia).
What are its main signs and symptoms?
The signs and symptoms of hypoparathyroidism are a result of the decreased levels of calcium in the blood.
- Symptoms indicating mild to moderate intensity of the condition include:
- Tingling sensations.
- Numbness and paraesthesia (an abnormal sensation) in the toes, fingers, and around the lips.
- Muscle aches.
- Generalized weakness.
- Headaches.
- Anxiety or nervousness.
- Dry and coarse skin.
- Patchy hair loss.
- Brittle nails.
- Depression.
- Symptoms indicating severe disorder include:
- Muscle spasms, which may also result in laryngospasm (spasm of the vocal cords) or bronchospasm (spasm of the tissue lining the lung airways- bronchi)
- Muscle cramps
- Uncommon symptoms that may occur in chronic cases include:
- Developmental anomalies of teeth known as enamel hypoplasia occur in children.
- Malformed tooth roots.
- Increased risk of tooth cavities.
- Hoarse voice.
- Wheezing.
- Dyspnoea (shortness of breath).
- Seizures.
- Fainting.
- Cardiac arrhythmias (a group of conditions where the heartbeat is abnormal- too fast, too slow, or irregular).
- Cloudiness in the eyes or cataract.
What are the main causes?
Hypoparathyroidism is caused due to a reduced secretion of parathyroid hormone by the parathyroid glands.
- Common causes include:
- Injury to or removal of the parathyroid glands during thyroid or neck surgery.
- Other causes include:
- Collateral damage while delivering radioactive iodine therapy for hyperthyroidism.
- It may occur in association with certain diseases involving the chromosomes (structures that carry the genetic material) such as, DiGeorge syndrome, adrenal hormone insufficiency or Addison's disease among others.
- Less than normal level of serum magnesium.
- Autoimmune diseases (a disease where an individual’s own immune system attacks the body’s cells and tissues) affecting parathyroid glands.
- The absence of parathyroid glands since birth (congenital hypoparathyroidism).
How is it diagnosed and treated?
Diagnosis is based on the symptoms, signs, detailed medical history, and a thorough clinical evaluation.
Investigations include:
- Blood tests to evaluate calcium, phosphorus, magnesium, and creatinine levels.
- Parathyroid hormone test.
- Urine test for assessing calcium excretion.
- Electrocardiogram (ECG) to check for heart rhythms and ophthalmologic consultation to check for cataract are also advised.
Treatment aims to provide relief from the symptoms and restore the balance of calcium and phosphorus levels in the bones and blood. Other treatment modalties include:
- Oral substitutes and supplements for calcium and vitamin D are prescribed.
- Parathyroid hormone injections may be needed.
- In severe cases, intravenous (in the veins) injections of calcium are administered.
- Monitoring vital signs (blood pressure, heart rate, breathing rate and body temperature) and heart rhythm are essential in severe cases.