TSH

Thyroid-stimulating hormone (TSH) is a hormone produced by the pituitary gland in the brain. It plays a crucial role in regulating the thyroid gland's function. 

Elevated TSH levels indicate an underactive thyroid gland (hypothyroidism). This can lead to symptoms such as fatigue, weight gain, sensitivity to cold, and depression. Low TSH levels indicate an overactive thyroid gland (hyperthyroidism). This can cause symptoms such as anxiety, rapid heart rate, weight loss, and bulging eyes.