What should you know about hyperthyroidism and rheumatoid arthritis?

Hyperthyroidism means the body is exposed to too much thyroid hormone. It may cause a fast or irregular heartbeat, heat intolerance, tremor, weight change, anxiety, or weakness. Rheumatoid arthritis is an inflammatory joint disease; many people with it develop finger stiffness, hand swelling, and joint pain, often with morning stiffness. A symptom such as joint stiffness does not by itself show that a person has rheumatoid arthritis. Clinicians combine the pattern of symptoms with examination and blood or imaging tests when appropriate.

Keep a record of palpitations, tremor, sleep changes, swollen joints, and how long morning stiffness lasts. Arrange medical review if symptoms persist or several joints become painful or swollen. Thyroid treatment and rheumatoid arthritis treatment are planned separately, with medicines checked for interactions and changes in heart rate, bone health, or infection risk. Do not start or stop anti-inflammatory medication without reviewing your medical history and other medicines. Learn more about [Rheumatoid Arthritis](/conditions/rheumatoid-arthritis/), [Hand Swelling](/symptoms/hand-swelling/), and [Anti-Inflammatory Medication](/treatments/non-surgical-orthopedics/anti-inflammatory-medication/).

Seek urgent care for chest pain, fainting, severe breathlessness, a very fast or irregular heartbeat, or sudden confusion. Prompt review is also appropriate for a hot, very swollen joint with fever, rapidly worsening weakness, or new inability to use a limb. These warning signs need assessment regardless of whether thyroid disease or rheumatoid arthritis is already diagnosed.

Ask which symptoms may be thyroid-related and which suggest joint inflammation, which tests are needed, and how your medicines will be monitored. Ask whether [Finger Stiffness](/symptoms/finger-stiffness/) or [Morning Joint Stiffness](/symptoms/morning-joint-stiffness/) should be documented, and when to report new [Joint Swelling](/symptoms/joint-swelling/).