- Underactive thyroid
- Hypo so low mood, slow, lethargic gain weight etc
- Most common in women and older people
Causes/Factors
The most common cause of hypothyroidism is autoimmune thyroiditis, also known as Hashimoto’s thyroiditis. Other factors and causes include:
Primary causes
- Medications: Certain drugs, such as Lithium and Amiodarone, can affect thyroid function.
- Iodine Deficiency: Inadequate intake of iodine, a crucial component for thyroid hormone production.
- Radiation Therapy: For Head and Neck cancers.
Secondary causes
Secondary hypothyroidism is often associated with a lack of other pituitary hormones, such as ACTH, referred to as hypopituitarism. This is rarer than primary hypothyroidism, and may be caused by damage to the pituitary in some way.
Symptoms
Symptoms of hypothyroidism can vary in severity and may include:
- Weight gain
- Fatigue
- Dry skin
- Coarse hair and hair loss
- Fluid retention (including oedema, pleural effusions and Ascites)
- Heavy or irregular periods
- Constipation
Signs
- Enlarged Thyroid (Goiter): Swelling of the thyroid gland - caused by iodine deficiency
- Slowed Reflexes: Delayed reflex responses.
Diagnostic Tests
Diagnosing hypothyroidism involves blood tests, including:
- Thyroid Function Tests: Measuring levels of thyroid hormones (T3 and T4) and thyroid-stimulating hormone (TSH).
- Antithyroid Antibody Test: To check for autoimmune causes.
- Thyroid Ultrasound: Imaging to assess thyroid gland size and structure.
Management
Treatment of hypothyroidism typically involves lifelong hormone replacement therapy with synthetic thyroid hormones, such as Levothyroxine. The goal is to restore thyroid hormone levels to normal and alleviate symptoms.
Sub-clinical hypothyroidism
Where TSH level is elevated but less than 10 mU/L on two separate occasions three months apart and symptoms of hypothyroidism are present
- 6-month trial of Levothyroxine and rechecking TFTs after.
- This is because patients with subclinical hypothyroidism have an increased risk of cardiovascular disease and progression to overt hypothyroidism, and treatment generally resolves symptoms.
Complications/Red Flags
Untreated or inadequately managed hypothyroidism can lead to complications, including:
- Cardiovascular Issues: Elevated cholesterol levels and an increased risk of heart disease.
- Mental Health Problems: Increased risk of Depression and cognitive impairment.
- Myxedema: A rare but life-threatening condition characterized by extreme hypothyroidism.