Thyroid disorders (hypo/hyperthyroidism)
When you visit your primary care doctor for possible thyroid problems, they will ask about your symptoms – such as fatigue, weight changes, temperature sensitivity, mood changes, changes in menstrual cycles, bowel habits, heart rate and eye or neck changes. They will feel your neck for an enlarged thyroid or lumps and review your medical history and medications. Because signs of thyroid dysfunction are nonspecific, diagnosis relies on blood tests that measure thyroid‑stimulating hormone (TSH) and free thyroxine (T4) levelshttps://www.aafp.org/pubs/afp/issues/2021/0515/p605.html#:~:text=Clinical%20hypothyroidism%20affects%20one%20in,levels%20are%20achieved%20with%20levothyroxine. High TSH with low T4 suggests hypothyroidism, whereas low TSH with high T4 and/or triiodothyronine (T3) points to hyperthyroidismhttps://my.clevelandclinic.org/health/diseases/14129-hyperthyroidism#:~:text=,lower%20than%20normal. The doctor may ask about family history of autoimmune disease or past radiation exposure and may check for eye symptoms or tremors. Pregnant or postpartum patients require special consideration because thyroid dysfunction can affect pregnancy and recovery.https://my.clevelandclinic.org/health/diseases/12120-hypothyroidism#:~:text=,threatening
• **Hypothyroidism:** The standard treatment is daily levothyroxine, a synthetic form of T4, which replaces the hormone your body lacks. Dosing is based on weight and monitored by TSH levels; older adults or those with heart disease start with lower doseshttps://www.aafp.org/pubs/afp/issues/2021/0515/p605.html#:~:text=Clinical%20hypothyroidism%20affects%20one%20in,to%20nine%20doses%20per%20week. Treatment is lifelong and medication should be taken on an empty stomach; adding triiodothyronine (T3) is not recommendedhttps://www.aafp.org/pubs/afp/issues/2021/0515/p605.html#:~:text=Clinical%20hypothyroidism%20affects%20one%20in,in%20patients%20with%20persistent%20symptoms.
• **Hyperthyroidism:** First‑line medications such as methimazole or propylthiouracil decrease hormone productionhttps://my.clevelandclinic.org/health/diseases/14129-hyperthyroidism#:~:text=; beta‑blockers (e.g., propranolol) control symptoms like palpitationshttps://my.clevelandclinic.org/health/diseases/14129-hyperthyroidism#:~:text=%23%20Beta. Radioactive iodine therapy destroys overactive thyroid tissue and often results in hypothyroidism that requires levothyroxinehttps://my.clevelandclinic.org/health/diseases/14129-hyperthyroidism#:~:text=. In some cases, surgery (thyroidectomy) is usedhttps://my.clevelandclinic.org/health/diseases/14129-hyperthyroidism#:~:text=. Your doctor will discuss options and monitor therapy closely to maintain normal hormone levels.
Common tests include:
• **Thyroid function tests:** A serum TSH level is the initial test; if abnormal, free T4 and sometimes total or free T3 are measured to distinguish between hypothyroidism and hyperthyroidismhttps://www.aafp.org/pubs/afp/issues/2021/0515/p605.html#:~:text=Clinical%20hypothyroidism%20affects%20one%20in,levels%20are%20achieved%20with%20levothyroxinehttps://my.clevelandclinic.org/health/diseases/14129-hyperthyroidism#:~:text=,lower%20than%20normal.
• **Thyroid antibodies:** Thyroid peroxidase (TPO) antibodies and thyrotropin receptor antibodies help identify autoimmune causes like Hashimoto’s or Graves’ diseasehttps://my.clevelandclinic.org/health/diseases/14129-hyperthyroidism#:~:text=,Graves%E2%80%99%20disease%20is%20the%20cause.
• **CBC and metabolic panel:** Evaluate for anemia, liver/kidney function and electrolyte abnormalities that may accompany thyroid disease or its treatment.
• **Lipid panel:** High cholesterol and triglyceride levels are common in hypothyroidismhttps://www.aafp.org/pubs/afp/issues/2021/0515/p605.html#:~:text=Signs%20and%20symptoms%20are%20nonspecific,on%20primary%20hypothyroidism%20in%20adults.
• **Pregnancy test:** Done when menstrual cycles are irregular or before certain treatments.
Additional tests, such as thyroid‑stimulating immunoglobulins, calcitonin, or vitamin D levels, may be ordered based on symptoms or family history.
Imaging is not usually needed for routine thyroid dysfunction. If a goiter or nodule is felt, ultrasound provides a safe, detailed picture of the gland. A radioactive iodine uptake (RAIU) scan helps determine the cause of hyperthyroidismhttps://my.clevelandclinic.org/health/diseases/14129-hyperthyroidism#:~:text=,test%20they%20think%20is%20best. CT or MRI of the neck or brain is reserved for complex cases involving large goiters, suspected cancer or pituitary disease.
Call your provider promptly if you notice unexplained weight gain or loss, persistent fatigue, extreme sensitivity to cold or heat, rapid heart rate or palpitations, tremors, anxiety, depression, changes in bowel patterns, swelling in your neck, bulging eyes, hoarse voice, or menstrual changes. Seek emergency care if you have confusion, severe lethargy, low body temperature or slow heart rate (possible myxedema coma)https://my.clevelandclinic.org/health/diseases/12120-hypothyroidism#:~:text=,to%20the%20ER, or fever and very fast heart rate (possible thyroid storm)https://my.clevelandclinic.org/health/diseases/14129-hyperthyroidism#:~:text=,is%20left%20untreated.
When starting or adjusting levothyroxine or antithyroid medication, your doctor will recheck TSH and T4 every 4–6 weeks until levels stabilize; after that, testing is usually done every 6–12 months. Pregnant patients need testing about every four weekshttps://www.aafp.org/pubs/afp/issues/2021/0515/p605.html#:~:text=Clinical%20hypothyroidism%20affects%20one%20in,persistent%20symptoms%20after%20adequate%20levothyroxine. If you undergo radioactive iodine therapy or surgery, follow-up includes frequent labs to monitor for hypothyroidism.
Thyroid disorders often arise from autoimmune conditions and can’t always be prevented. However, you can support thyroid health by eating a balanced diet with adequate (but not excessive) iodine, selenium and zinc; avoiding smoking; and managing stress. Limit unnecessary exposure to radiation (e.g., repeated neck CT scans). If you’re pregnant or planning pregnancy, discuss thyroid screening. See your provider promptly if symptoms arise; early diagnosis and treatment reduce the risk of complications.
Your primary care doctor will coordinate your evaluation and treatment. They may refer you to an endocrinologist for complex cases, including difficulty achieving normal hormone levels, pregnancy, planning pregnancy, or hyperthyroidism requiring radioactive iodine or surgery. A surgeon may remove part or all of your thyroid if nodules or cancer are present. An ophthalmologist may be involved if you develop eye symptoms (Graves’ orbitopathy), and a cardiologist may help manage heart rhythm problems. Pharmacists, dietitians and mental health providers can assist with medication management, nutrition and coping strategies.