What are the other Names for this Condition? (Also known as/Synonyms)

• Hyperparathyroidism, Primary type
• Overactive Thyroid Gland due to Primary Hyperparathyroidism

What is Primary Hyperparathyroidism? (Definition/Background Information)

• Primary Hyperparathyroidism is a condition that occurs when the parathyroid glands located on the neck, secrete abnormally high levels of parathyroid hormone (PTH). It is generally observed in older (postmenopausal) women
• Hyperparathyroidism is considered primary, when it occurs due to dysfunction of the gland itself, not due to factors extrinsic to the gland. Secondary hyperparathyroidism indicates that the dysfunction is caused by factors extrinsic to the thyroid gland (i.e., not due to a disorder in the gland)
• A family history of the condition and severe prolonged calcium or vitamin D deficiency are risk factors for Primary Hyperparathyroidism. However, the most common cause is a benign tumor on one or more of the parathyroid glands that causes an increased release of parathyroid hormone
• Initial signs and symptoms of Primary Hyperparathyroidism include muscle weakness, joint pain, and overall fatigue. Severe hyperparathyroidism can result in osteoporosis and other clinical cardiovascular complications. It is typically diagnosed during a routine blood test that shows elevated levels of PTH along-with hypercalcemia (increased calcium in blood)
• Primary Hyperparathyroidism can be treated by a combination of methods including close monitoring, medication, or surgery, depending on the severity and nature of hyperparathyroidism
• Although there are no definitive methods of prevention for Primary Hyperparathyroidism, the prognosis is good for the majority of individuals who receive adequate treatment

Who gets Primary Hyperparathyroidism? (Age and Sex Distribution)

• Primary Hyperparathyroidism is a rare condition that can affect both males and females
• It is typically seen in individuals over the age of 60, but women are about 2-3 times as likely to develop Primary Hyperparathyroidism as men
• Individuals of all races, ethnicities, and geographic locations can be affected

What are the Risk Factors for Primary Hyperparathyroidism? (Predisposing Factors)

The following factors can increase one’s risk for Primary Hyperparathyroidism:

• A family history of Primary Hyperparathyroidism or endocrine disorders
• Postmenopausal women
• Prolonged and severe calcium or vitamin D deficiency
• Lithium therapy
• Exposure of the neck to radiation therapy

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Primary Hyperparathyroidism? (Etiology)

Primary Hyperparathyroidism is caused by an abnormality in one or more parathyroid glands which leads to excess production of parathyroid hormone (PTH). Although most cases have an unknown cause, the following are known to cause Primary Hyperparathyroidism:

• A benign growth on the parathyroid gland causes the gland to grow larger causing excess PTH secretion into the bloodstream
• An enlargement (hyperplasia) of parathyroid glands

Less common causes can include:

• Medical conditions such as kidney failure or rickets
• A cancerous tumor on the parathyroid gland

What are the Signs and Symptoms of Primary Hyperparathyroidism?

Primary Hyperparathyroidism generally does not show immediate signs and symptoms. Signs and symptoms are typically due to high calcium levels in blood (hypercalcemia) because of excess parathyroid hormone (PTH) releasing calcium from the bones.

The signs and symptoms of Primary Hyperthyroidism develop slowly over time. The initial presentations may include: 

• Muscle fatigue or weakness
• Overall fatigue requiring larger amounts of sleep
• Pain in bones
• Depression 
• Frequent heartburn or abdominal pain

Individuals with severe cases of Primary Hyperparathyroidism may have signs and symptoms which include:

• Forgetfulness
• Constipation
• Increased thirst and urination
• Loss of appetite
• Nausea
• Increased bone fractures due to weakening of bones (osteoporosis)

How is Primary Hyperparathyroidism Diagnosed?

Primary Hyperparathyroidism is diagnosed following a complete evaluation of one’s medical history and a thorough physical examination. High calcium levels in blood due to excessive parathyroid hormone are usually detected through routine blood tests.

Other tests to confirm or assess damage of overactive parathyroid gland may include:

• Urine tests to detect excreted calcium levels
• Bone mineral density test
• Ultrasound scan of the neck region
• CT scan of head and neck region
• Vitamin D blood test

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Primary Hyperparathyroidism?

Complications associated with Primary Hyperparathyroidism can include:

• Formation of kidney stones
• Bone fractures due to osteoporosis
• High blood pressure (hypertension)
• Cardiovascular disease
• Neonatal hyperparathyroidism (in newborn babies) if hyperparathyroidism is left untreated in pregnant mothers

How is Primary Hyperparathyroidism Treated?

The treatment of Primary Hyperparathyroidism may include:

Monitoring the condition: Those with only mild signs and symptoms may require routine doctor visits to check for:

• Vitamin D levels
• Bone density measurements
• Serum calcium and creatinine levels

Plenty of water and exercise should be incorporated into one’s daily regimen. 

The medications used to treat Primary Hyperparathyroidism include:

• Bisphosphonates to retain calcium in bone
• Selective estrogen receptor modulators
• Cinacalcet (a medication that mimics calcium and helps reduce the production of PTH)

Surgery: Surgery is generally the definitive treatment but may not be used for every case. Individual with extremely high levels of calcium as a result of excessive PTH are strong candidates for surgery. The potential surgical procedures include:

• Standard neck exploration
• Parathyroidectomy (can be total or subtotal removal of the parathyroid gland)

How can Primary Hyperparathyroidism be Prevented?

Presently, there are no prevention methods associated with Primary Hyperparathyroidism.

• Knowledge about one’s family history is helpful to assess or predict future risk for the condition 
• Individuals at risk should refrain from smoking and regularly follow-up with a healthcare provider for ensuring early detection

What is the Prognosis of Primary Hyperparathyroidism? (Outcomes/Resolutions)

The prognosis of Primary Hyperparathyroidism is generally good with appropriate treatment.

• However, individuals may either require lifelong medications to keep the symptoms under control or a surgical removal of the parathyroid gland, and periodic health monitoring
• Surgical removal may necessitate parathyroid hormone replacement to prevent hypoparathyroidism (abnormally decreased levels of parathyroid hormone in the body)

Additional and Relevant Useful Information for Primary Hyperparathyroidism:

Individuals with Primary Hyperparathyroidism should strictly limit their daily intake of calcium to avoid increasing the already elevated levels of calcium.