Thyroid disease is a general term for a medical condition that keeps your thyroid from making the right amount of hormones. It can affect people of all ages. The thyroid is a small, butterfly-shaped gland located at the front of your neck under your skin. It’s a part of your endocrine system and controls many of your body’s important functions by producing and releasing thyroid hormones, like thyroxine (T4) and triiodothyronine (T3). The thyroid’s main job is to control the speed of your metabolism (metabolic rate). This is the process of how your body transforms the food you consume into energy. All the cells in your body need energy to function. When your thyroid isn’t working properly, it can impact your entire body.
Types of thyroid disease:
The two main types of thyroid disease are hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid).
Conditions that can cause hypothyroidism include:
- Hashimoto’s disease: This is a lifelong (chronic) autoimmune condition that can cause an underactive thyroid. It’s the most common cause of hypothyroidism in countries with widely available iodised salt and other iodine-enriched foods.
- Iodine deficiency: Your thyroid needs iodine to make thyroid hormone, so a lack of the mineral in your diet can lead to hypothyroidism. It’s the most common cause of hypothyroidism in countries that don’t have iodised salt widely available. It often causes goitre (enlarged thyroid).
- Congenital hypothyroidism: Sometimes, babies are born with a missing or underactive thyroid. “Congenital” means “present from birth.” About 1 in every 2,000 to 4,000 babies has congenital hypothyroidism.
Conditions that can cause hyperthyroidism include:
- Graves’ disease: This is a chronic autoimmune condition that causes an overactive thyroid. It’s the most common cause of hyperthyroidism.
- Thyroid nodules: These are abnormal lumps on your thyroid gland. If the nodules are hyperfunctioning, they can lead to hyperthyroidism.
- Excessive iodine: When you have too much iodine in your body, your thyroid makes more thyroid hormones than you need. You may develop excessive iodine by taking certain medications, like amiodarone (a heart medication).
What are the symptoms of thyroid disease?
There are a variety of symptoms you could experience if you have thyroid disease. Unfortunately, symptoms of a thyroid condition are often very similar to the signs of other medical conditions and stages of life. This can make it difficult to know if your symptoms are related to a thyroid issue or something else entirely.
Symptoms of hypothyroidism include:
- Slower-than-usual heart rate.
- Feeling tired (fatigue).
- Unexplained weight gain.
- Feeling sensitive to cold.
- Dry skin and dry and coarse hair.
- Depressed mood.
- Heavy menstrual periods (menorrhagia).
Symptoms of hyperthyroidism include:
- Faster-than-usual heart rate (tachycardia).
- Difficulty sleeping.
- Unexplained weight loss.
- Feeling sensitive to heat.
- Clammy or sweaty skin.
- Feeling anxious, irritable or nervous.
- Irregular menstrual cycles or a lack of periods (amenorrhea)
- Both conditions can cause an enlarged thyroid (goitre), but it’s more common in hyperthyroidism.
