Here, the high level of parathyroid hormone is caused by another condition or deficiency. This condition causes chronic low calcium levels in your blood and your parathyroid glands have to work extra hard to try to raise your blood calcium level and release more parathyroid hormone. Tests will usually show a raised level of parathyroid hormone and a low blood calcium level.
- If you have an intestinal or gut condition, such as Crohn’s Disease, you may have a problem absorbing calcium from your food into your blood causing persistently low calcium levels.
- Vitamin D deficiency (which can cause rickets in children or osteomalacia in adults) is another common cause of chronic low level of calcium in your blood.
- The most common cause of Secondary Hyperparathyroidism is kidney disease. It occurs in nearly all people who are on long-term kidney dialysis because of kidney failure. Because you have kidney failure, your blood calcium level can become chronically low.
In Secondary Hyperparathyroidism, you will have symptoms of low, NOT high, calcium which can be seen here. You may develop bone complications such as osteopaenia or osteoporosis and the symptoms related to that.
In Secondary Hyperparathyroidism, you will have a low or normal calcium level with a raised parathyroid hormone level. In kidney disease, your blood phosphate level can be high because your kidneys cannot remove phosphate in your urine.
In Secondary Hyperparathyroidism the underlying condition should be treated; for example, vitamin D deficiency should be treated with vitamin D supplements. Early treatment of Secondary Hyperparathyroidism can prevent bone complications and reduce the chance of Tertiary Hyperparathyroidism.
Surgery to remove parathyroid glands in Secondary Hyperparathyroidism would only be considered in certain severe conditions eg end stage renal failure.
Chronic kidney disease:
If you have chronic kidney disease, treatment may include:
- Drugs to lower blood pressure.
- Diet to lower your phosphate level (limits of milk, cheese, eggs and dairy products). You may also need some medication such as calcium carbonate which binds to phosphate and helps to stop it being absorbed from your gut after you have eaten.
- Calcium supplements and active Vitamin D (such as Alfacalcidol or Rocaltrol) to raise your calcium level as vitamin D3 can no longer be converted to the active form of vitamin D by your kidneys
- You will be monitored with regular blood tests and should have an eGFR test annually.
- Follow a low phosphate diet
- Limit salt in your diet
- Drink about 2 litres of water daily
- Lose weight if necessary
- Stop smoking
- Take regular exercise.
For further information on kidney disease please visit the NHS information page here, or The National Kidney Federation here