Doctors Explain Signs You Have an Over- or Underactive Thyroid

# Doctors Explain Signs You Have an Over- or Underactive Thyroid

Your thyroid controls metabolism, heart rate, and body temperature. When it malfunctions, the symptoms can feel vague enough to dismiss or attribute to stress, aging, or poor sleep.

Endocrinologists identify distinct patterns that separate an overactive thyroid (hyperthyroidism) from an underactive one (hypothyroidism).

With hypothyroidism, your metabolism slows. You gain weight despite eating normally. Fatigue becomes persistent, even after adequate sleep. Your skin dries out. Hair thins or falls out. Brain fog settles in. Cold sensitivity intensifies. Constipation worsens. Women may experience heavier periods. These changes often develop gradually, making them easy to overlook.

Hyperthyroidism produces the opposite effect. Your metabolism accelerates. Unexplained weight loss occurs alongside increased appetite. Your heart races or develops an irregular beat. Anxiety spikes without obvious triggers. You sweat excessively, even in cool environments. Tremors develop in your hands. Sleep becomes difficult. Some people experience eye changes, including bulging or sensitivity to light.

Both conditions share one overlooked symptom: mood changes. Depression frequently accompanies hypothyroidism. Irritability and anxiety characterize hyperthyroidism.

The challenge lies in recognizing these patterns. A 45-year-old woman attributing weight gain and fatigue to middle age may actually have hypothyroidism. A young adult dismissing heart palpitations as anxiety might have Graves' disease, an autoimmune thyroid disorder.

Endocrinologists stress that blood tests confirm what symptoms suggest. TSH (thyroid-stimulating hormone) and free T4 levels reveal your thyroid's actual function. Testing becomes essential if you experience multiple