Low metabolism

Low metabolism

Low metabolism, or hypothyroidism, is reduced production of the hormones that regulate metabolism. About 1% of men and 5% of women are affected by low metabolism. Children can also be affected by low metabolism, but this is more rare. It can be difficult to detect a low metabolism because the symptoms come on gradually and are often non-specific.

How is the body's metabolism regulated?

The body's metabolism is regulated by a careful cooperation between a center in the brain (hypothalamus), a gland in the brain (pituitary gland) and the thyroid gland (thyroid).

The pituitary gland regulates production of the metabolic hormones thyroxine and triiodothyronine in the thyroid gland. These hormones regulate the body's metabolism/combustion and are also necessary for a number of other organs in the body to function normally.

Too little thyroxine and triiodothyronine results in low metabolism (hypothyroidism), while too much results in high metabolism (hyperthyroidism).

Causes of low metabolism

In 98% of cases, low metabolism is due to failure of the thyroid gland. The most common cause of thyroid failure is chronic inflammation, an autoimmune disease where the body's own immune system attacks the thyroid gland.

Other causes of low metabolism can be:

• Failure of the pituitary gland or hypothalamus.

• Radiotherapy or thyroid surgery.

• Diabetes, arthritis and celiac disease can increase the risk of low metabolism.

• Pregnancy (normally transient).

• Iodine deficiency .

• Insufficient development of the thyroid gland (congenital).

• Side effect of medication.

Symptoms of low metabolism

Low metabolism can be very difficult to detect because the symptoms often come on gradually and are non-specific. Typical symptoms can be:

Fatigue and increased need for sleep.

• That you freeze easily.

• Constipation.

• Dry and cold skin, tingling in the skin and brittle nails.

• Dry and split hair, hair loss.

• Weight gain (rarely more than 3 kilos).

• Muscle and joint pain.

• Slower movements.

• Low mood / depression / listlessness.

• Concentration problems.

Treatment of low metabolism

Low metabolism is treated by adding synthetically produced hormones. Usually thyroxine is used in tablet form alone, but sometimes also in combination with triiodothyronine. The medication is normally lifelong.

Tablets against low metabolism easily bind to iron, calcium, magnesium and some medicines. This can reduce the absorption of the active substance and give a lower effect. You should therefore avoid dietary supplements with calcium, magnesium or iron, foods with iron (goat cheese, liver), dairy products (cheese, milk, yoghurt) and certain medicines (for example tablets against heartburn and acid reflux) 2 hours before and after tablet intake.

If you have used such tablets for years and always taken them with milk or magnesium, for example, you should not change your routine without talking to your doctor first. A change creates a risk of overdose. Overdose over time increases the chance of osteoporosis.

When should you contact a doctor if your metabolism is low?

• If you think you may have a low metabolism

• If you have heart disease and notice a change when you use thyroxine

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Sources: Norwegian drug handbook for healthcare personnel, Norwegian health informatics for healthcare personnel and the Joint Catalogue.