The parathyroid hormone is incredibly important, and yet few people know about it or understand how it functions. Understanding how the parathyroid works and what it does can give us all insight into one of the most fascinating systems in the human body. It is important to note that the parathyroid system has nothing to do with the thyroid system that controls human metabolism. The parathyroid gets its name because the parathyroid glands are located near the thyroid gland, not because they are involved in the same processes.
What is the Parathyroid Hormone?
The parathyroid hormone controls the level of calcium in the blood. Blood levels of calcium must remain between 9 and 10 for optimum health, and the role of the parathyroid system is to ensure that this level remains steady and doesnt change.
Why is Calcium Important?
We all know that calcium is an important mineral for good health, especially in the bones and teeth. Without sufficient calcium, the bones become less dense and more brittle, which makes them more prone to breaking. While we may consider strong bones to be the most important task for calcium in the body, the role of calcium in the brain is actually an even more important function. The bones are essentially a place for our bodies to store calcium for use inside the brain and nervous system.
Calcium is essential for communication by neurotransmitters in the brain and is also used for important mental processes such as memory. Calcium is an important component of the nervous system. Calcium makes it possible for electrical impulses to travel along the nerves, sending messages from one nerve cell to another. This process is crucial to life. In the muscular system, calcium is responsible for the normal function of muscle contraction, enabling us to move, balance and lift things.
How does the Parathyroid Hormone Control Calcium Levels?
The parathyroid hormone is produced by the parathyroid endocrine glands. We all have four of these glands which are only the size of a grain of rice! These glands basically function as a calcium monitor. They are constantly checking the blood and monitoring its calcium level. This is happening all the time; while you work and even while you sleep. When the parathyroid gland detects that the level of calcium has dropped too low or become too high, it deals with this by decreasing or increasing how much parathyroid hormone it is producing.
The parathyroid glands release the parathyroid hormone into the blood where it gets to work in managing the calcium level. So, when the blood calcium level is too low, the parathyroid hormone removes calcium from the bones to increase the calcium level in the blood. If the blood calcium level is too high, the parathyroid glands produce less of the hormone, and this allows the blood calcium level to increase. By carefully monitoring the blood level, the parathyroid glands are able to respond quickly and proportionately to even the smallest of fluctuations in the blood calcium level, and this results in a steady blood calcium level. The parathyroid glands never stop monitoring the blood and altering the production of the parathyroid hormone.
How does the Parathyroid Hormone Work?
Parathyroid hormone alters the serum level of calcium (how much calcium is in the blood) by acting on the bones, intestines, and kidneys. The hormone acts on the bones and makes them release their stores of calcium. This decreases how much new bone is produced and can decrease the density of the existing bones and weaken them. In the intestines, parathyroid hormone increases how much calcium is absorbed from the foods we eat. In the kidneys, the hormone ensures that less calcium is excreted as waste in the urine. To increase how much calcium is absorbed and decrease how much is excreted, the hormone alters the production of vitamin K.

Parathyroid Disorders
If the parathyroid is not functioning correctly to monitor calcium levels and produce the right amount of parathyroid hormone, there are a number of negative effects.
Hyperparathyroidism is when the parathyroid does not regulate the calcium levels correctly. If too much of the regulating hormone is released by faulty parathyroid glands, then too much calcium is taken from the bones. This can cause osteoporosis (a condition where the bones become porous and weak) other consequences of parathyroid dysfunction include kidney problems, blood pressure problems, high risk of stroke, heart rhythm issues. If untreated, this condition can be extremely dangerous for the body.
Signs of Parathyroid Disorders
Symptoms of parathyroid problems can include aches and pains, headaches, memory issues, concentration problems, depression, insomnia, and extreme tiredness. Parathyroid dysfunction is usually caused by a tumor in the parathyroid which produces too much of the parathyroid hormone. This is a non-cancerous condition, but the tumor must be removed in order to stop the dangerous effects of the condition.
Calcium levels can be easily checked with a blood test; high levels are a major sign of a problem with the parathyroid and is a sign that the patient is producing too much parathyroid hormone. It is much rarer to find that the level of hormone in the body is too low. This is known as hypoparathyroidism and is usually treated by supplementing with calcium and vitamin D. Regular blood tests to keep a check on the serum calcium level are important, especially as we grow older. High calcium levels are an indication that the patient needs to be checked for hyperparathyroidism. Dealing with parathyroid problems can have a huge impact on how a person feels and their quality of life, so it is important to identify any issues and deal with them promptly.