Hypothyroidism symptoms are caused by insufficient thyroid hormone production, leading to a slowed metabolism and widespread effects on the body. Symptoms often develop gradually and can vary between individuals, but common signs include:

• Fatigue and weakness: Persistent tiredness that isn’t relieved by sleep.

• Weight gain: Unexplained increase in weight, often due to fluid retention and reduced metabolic rate.

• Cold intolerance: Feeling cold even in warm environments.

• Dry, rough skin and brittle nails: Reduced sweat and sebum production.

• Hair loss and thinning: Hair becomes coarse, dry, and may fall out, sometimes with loss of the outer third of the eyebrows (Queen Anne’s sign).

• Constipation: Slowed digestion due to reduced gut motility.

• Depression and mood changes: Low mood, irritability, anxiety, or apathy.

• Cognitive issues: "Brain fog," difficulty concentrating, memory problems, and slowed thinking.

• Muscle and joint pain: Aches, stiffness, or weakness.

• Menstrual irregularities: Heavy or frequent periods (menorrhagia), or irregular cycles.

• Puffy face and swelling: Non-pitting edema (myxedema), especially around the eyes and hands.

• Hoarse voice and slowed speech: Due to tissue swelling and reduced nerve conduction.

• Low heart rate (bradycardia): A slower-than-normal pulse.

• High cholesterol: Often linked to untreated hypothyroidism.

Symptoms may be subtle at first and easily mistaken for aging, stress, or other conditions. In some cases, less common symptoms include shortness of breath, swollen tongue, vision changes, frequent urination, or a feeling of choking in the throat.

Note: Hypothyroidism is more common in women and individuals over age 60. The most common cause is Hashimoto’s disease, an autoimmune condition. Diagnosis is confirmed via blood tests measuring TSH, T4, and thyroid antibodies. Treatment involves lifelong thyroid hormone replacement (e.g., levothyroxine), which typically reverses symptoms over time.