Hypothyroidism can be difficult to diagnose, as it can mimic many other conditions. Read our guide to get an idea of what to expect.
The thyroid gland, located in the neck, plays a large part in the control of your body’s metabolism. Hypothyroidism, also called underactive thyroid disease, occurs when your thyroid gland doesn’t produce enough thyroid hormone.
What causes hypothyroidism?
The most common cause of hypothyroidism is a condition called Hashimoto’s thyroiditis. This autoimmune disorder is caused by your body attacking the thyroid gland with antibodies.
While it’s responsible for the majority of cases, Hashimoto’s thyroiditis is far from the only cause of hypothyroidism. Others include:
- Radiation therapy to the neck area
- Radioactive iodine treatment
- Certain medications
- Thyroid surgery
- Too little iodine in the diet
Inflammation of the thyroid can also occur after pregnancy in some cases.
Certain people are more at risk of hypothyroidism than others as well. Particularly, older people and those with autoimmune disorders fall into this category.

The symptoms of hypothyroidism
Hypothyroidism presents a varied range of symptoms, often making diagnosis difficult.
Symptoms include:
- Constipation
- Depression
- Dry hair and hair loss
- Dry skin
- Fatigue
- Increased sensitivity to cold
- Slowed heart rate
- Swelling of the thyroid gland
- Unexplained weight gain or difficulty in losing weight
Treating hypothyroidism
Luckily, treating hypothyroidism is reasonably simple. Once diagnosed, your doctor will prescribe a synthetic thyroid hormone, to be taken daily.
Unfortunately, this medication can interfere with your body’s ability to absorb thyroid hormone, so it’s important to make your doctor aware of any and all medications and supplements you take.
Once you’ve begun treatment, regular blood tests are needed to monitor thyroid hormone levels. This may lead to adjustments to your medication over time.