Hypothyroidism

Overview

The thyroid is a small butterfly-shaped gland in the neck, just in front of the windpipe. It produces hormones that regulate your heart rate and body temperature. 

Hypothyroidism (also called having an underactive thyroid gland) is where the thyroid gland does not produce enough hormones. Many of the body’s functions slow down when the thyroid does not produce enough hormones.

Key Facts

• Hypothyroidism is common, especially among older women
• The most common cause is an autoimmune disease that attacks the thyroid gland
• Hypothyroidism usually develops slowly 

Symptoms & Diagnosis

Symptoms

Many symptoms usually develop slowly, and you may not realise you have a medical problem for several years, so if you experience these over time, please speak with your doctor for further investigation:

• Tiredness
• Being sensitive to cold
• Weight gain
• Constipation
• Depression
• Slow movements and thoughts
• Muscle aches and weakness
• Muscle cramps
• Dry and scaly skin
• Brittle hair and nails
• Loss of libido (sex drive)
• Pain, numbness and a tingling sensation in hand and fingers (carpal tunnel syndrome)
• Irregular periods or heavy periods

Older people with an underactive thyroid may also have memory problems and depression. Whereas children may experience slower growth and development.

Diagnosis

If you experience these symptoms, speak with your doctor, who will take a complete health history and conduct a blood test to check your thyroid hormone levels.

The test checks the levels of the following elements:

• Thyroid-stimulating hormone (TSH) – this is a hormone produced by the pituitary gland, which is located at the base of your brain and controls the production of thyroid hormones
• Triiodothyronine (commonly referred to as T3) – it is one of the main thyroid hormones
• Thyroxine (also known as T4) – this is another of the main thyroid hormones

 A low level of T4 and a high level of TSH indicate an underactive thyroid. 

Other blood tests may be conducted to help identify potential causes of the overactive thyroid and its impact on your body. This will help evaluate the best course of treatment for you. A scan may also be conducted to explore potential lumps or other problems on your thyroid.

Causes & Prevention

Causes

The leading causes of underactive thyroid are the immune system attacking the thyroid gland or damage occurring as a side effect of treatment for thyroid cancer or an overactive thyroid.

A problem with your pituitary gland, which is located at the base of your brain and controls the production of thyroid hormones, can also lead to an underactive thyroid. 

Prevention

Unfortunately, there is no way to prevent hypothyroidism, but screening through the blood tests recommended by your doctor can help with early detection if you have any of the following risk factors:

• A history of autoimmune disease
• Previous radiation treatment to the head or neck
• Goitre
• Family history of thyroid problems
• Use of medications known to affect thyroid function

Treatments

The most common treatment for hypothyroidism involves taking daily hormone replacement tablets, which supplement and improve your thyroxine levels. Your doctor will conduct regular blood tests to ensure you reach the correct medication dosage.

This medication will likely be part of the rest of your life, and with proper management, you should lead an everyday, healthy life. However, if hypothyroidism is not treated, it can lead to other complications such as heart disease, goitre and potential pregnancy problems.

Conclusion

Undertreatment of hypothyroidism leads to disease progression, gradually worsening symptoms and further complications. However, In most patients, treatment reverses the signs and symptoms of hypothyroidism.