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

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

What is Secondary Hyperparathyroidism? (Definition/Background Information)

• Secondary 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 secondary, when it occurs due to factors extrinsic to the parathyroid gland, and not due to a dysfunction of the gland itself as seen in primary hyperparathyroidism
• Severe prolonged calcium or vitamin D deficiency are risk factors for Secondary Hyperparathyroidism. However, the most common cause is kidney failure in which the kidneys cannot process phosphorous in blood, resulting in low levels of vitamin D  
• Initial signs and symptoms of Secondary 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 which shows elevated levels of PTH along with hypocalcemia (decreased calcium in blood)
• Secondary Hyperparathyroidism can be treated by a combination of methods including close monitoring and medication depending on the severity and nature of hyperparathyroidism 
• Although there are no definitive methods of prevention for Secondary Hyperparathyroidism, the prognosis is good for the majority of individuals who receive adequate treatment

Who gets Secondary Hyperparathyroidism? (Age and Sex Distribution)

• Secondary 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 Secondary Hyperparathyroidism as men
• Individuals of all races, ethnicities, and geographic locations can be affected

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

The following factors can increase ones risk for Secondary Hyperparathyroidism:

• Old age: Postmenopausal women are at a high risk
• Prolonged and severe calcium or vitamin D deficiency
• Kidney failure
• Individuals living in environments where they receive little to no direct sunlight

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 Secondary Hyperparathyroidism? (Etiology)

Secondary Hyperparathyroidism is caused by a deficiency in calcium as a result of a set of factors or conditions that lower blood (serum) calcium levels. This leads to excess production of parathyroid hormone (PTH). There are multiple sets of causal factors that may result in Secondary Hyperparathyroidism.

The following are known to be associated with decreased calcium levels resulting in Secondary Hyperparathyroidism:

• Medical conditions such as chronic kidney failure or rickets
• Low intake levels of calcium resulting in calcium deficiency
• Severe vitamin D deficiency

What are the Signs and Symptoms of Secondary Hyperparathyroidism?

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

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

• Muscle fatigue or weakness
• Overall fatigue resulting in the individual needing larger amounts of sleep
• Pain in bones
• Depression 
• Frequent heartburn or abdominal pain

Those with severe Secondary 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 Secondary Hyperparathyroidism Diagnosed?

Secondary Hyperparathyroidism is diagnosed following a complete evaluation of one’s medical history and a thorough physical examination. Parathyroid hormone, phosphate, and calcium levels are usually detected through routine blood tests and may help a healthcare specialist determine the causal factors.

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

• Urine tests to detect excreted calcium levels
• Bone mineral density test
• Vitamin D blood test
• Imaging studies of the head and neck region, as needed

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 Secondary Hyperparathyroidism?

Complications associated with Secondary 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 Secondary Hyperparathyroidism Treated?

The treatment of Secondary Hyperparathyroidism may include:

Monitoring the condition: Those with only mild 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 Secondary 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) 

In individuals with Secondary Hyperparathyroidism, surgery is never typically a treatment option because the condition is not due to one specific causal factor on the parathyroid gland, as noted in primary hyperparathyroidism.

How can Secondary Hyperparathyroidism be Prevented?

Presently, there are no definitive prevention methods associated with Secondary Hyperparathyroidism.

• It is helpful to maintain normal calcium and vitamin D intake in order to reduce one’s risk for the same (especially in those at a high 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 Secondary Hyperparathyroidism? (Outcomes/Resolutions)

• The prognosis of Secondary Hyperparathyroidism is generally good with appropriate treatment
• However, individuals may require lifelong medications to keep the symptoms under control, including maintenance of calcium and vitamin D levels, and periodic health monitoring

Additional and Relevant Useful Information for Secondary Hyperparathyroidism:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/