Calcium plays a very important role in various bodily functions, like muscle contraction, hormone release, and bone formation. This mineral ensures the proper functioning of the brain and the nerves. The level of calcium in the blood is regulated by calcitonin (produced by thyroid gland), and parathyroid hormone (produced by parathyroid glands). However, in some people, the blood calcium levels rise above normal due to various reasons. Such a condition is termed hypercalcemia, which can affect most of the bodily functions mentioned above.
What Causes Hypercalcemia?
Calcium is absorbed by the body from foods, like milk, dairy products, and green leafy vegetables. Such calcium is stored in the bones. Excess calcium is excreted through the urine. All these are functions are regulated by various mechanisms, like the action of parathyroid hormone and calcitonin. In normal cases, a drop in the blood calcium level is countered by excess production of parathyroid hormone; which in turn stimulates release of calcium from bones, absorption of calcium from the digestive system, and reduction in the rate of excretion of the mineral by the kidneys. It also activates vitamin D, which aids absorption of calcium in the body. If the blood calcium level rises above normal, the body produces less parathyroid hormone; which curtails calcium absorption from the digestive tract, and release of the mineral from the bones.
In case of high levels of blood calcium, thyroid gland produces calcitonin, which inhibits the release of calcium from the bones. In some cases, these natural checks and balances in the body, do not work properly. One of the prominent causes for hypercalcemia is hyperactive parathyroid glands, which produce parathyroid hormone in excess. This condition is called hyperparathyroidism, which may affect any one or all four of the parathyroid glands.
Certain cancers, like lung cancer, breast cancer, and blood cancer, can cause hypercalcemia. Tuberculosis, sarcoidosis, infectious lung diseases, familial hypocalciuric hypercalcemia (genetic disorder), kidney failure, hyperthyroidism, excess intake of foods rich in calcium or calcium supplements may also lead to hypercalcemia. In some cases, medication, like thiazide diuretics are found to cause this condition. Dehydration and immobilization for very long periods may also cause a rise in blood calcium level.
The symptoms may vary from one patient to another. In case of mild hypercalcemia, the person may not have any symptom at all. However, those with severe hypercalcemia may exhibit some of the following symptoms.
- The most common symptoms include, tiredness, nausea and vomiting, constipation, pain in the abdomen, muscle and joint pain, loss of appetite, excessive thirst, and frequent urination.
- Hypercalcemia affects other systems and organs, like the nervous system, cardiovascular system, bones, kidneys, and the digestive system. If a particular system or organ is affected badly, the symptoms would be mostly related to that part.
- In case of the nervous system, the patient may experience headaches, difficulty in thinking and concentrating, and difficulty in speaking clearly.
- Hypercalcemia can affect the normal functioning of the heart, and may cause irregular heart beats (arrhythmia), and even a heart attack.
- If the kidneys are affected due to hypercalcemia, the symptoms include production of large volumes of urine and frequent urination. If the person consumes less water, dehydration may also result. Other symptoms include dry mouth, absence of sweating, and concentrated urine.
Disclaimer: This article is for informational purposes only, and should not be used as a replacement for expert medical advice. Visiting your physician is the safest way to diagnose and treat any health condition.