The thyroid is a small gland just below the Adam’s apple. This gland is very important in controlling the body’s metabolism. It does this by producing thyroid hormones (T3 and T4) that travel through the blood to all parts of the body—telling it how fast to work. The production of these hormones is under the influence of another hormone, TSH, which is produced by the pituitary gland. The thyroid gland might produce too many hormones (hyperthyroidism) or too few hormones (hypothyroidism).
| Symptoms of Hyperthyroidism | Symptoms of Hypothyroidism |
| Fatigue | Feeling lethargic or tired |
| Muscle weakness | Muscle cramps |
| Appetite change | Dry hair & hair loss |
| Weight loss | Weight gain |
| Diarrhea | Constipation |
| Nervousness | Feeling depressed |
| Heat intolerance | Feeling cold/cold intolerance |
| Increased perspiration | Memory loss |
| Insomnia | Slow heart rate |
| Light or missed menstrual period | Abnormal menstrual flow |
| Bulging of the eyes | Low level of T3 & T4 |
| Skin changes | High level of TSH |
| Hair loss | |
| Fast heart rate & shortness of breath | |
| High levels of T3 & T4 | |
| Low level of TSH |
What causes hyperthyroidism?
- The entire thyroid gland may be overactive (excess hormone).
- One or more lumps in the gland may be overactive.
- The gland may be inflamed (thyroiditis).
What causes hypothyroidism?
- Thyroid surgery or radioactive iodine treatment.
- Being born without a working thyroid gland.
- An inflammation of the thyroid gland (thyroiditis).
How are hyper and hypothyroidism clinically diagnosed?
- Patient history and physical appearance
- Examining the amount of thyroid hormones in the blood:
- T3 and T4
- Thyroid-stimulating hormone (TSH)
- Thyroid antibodies
MedLabs Suggested Thyroid Panel
- Free T3
- Free T4
- TSH
Additional (Optional) Tests:
- TPO
- Thyroid Microsomal Antibodies
- Thyroglobulin Antibodies
- TSH Receptor Antibody
- Thyroglobulin