Symptoms That Could Indicate Hyperthyroidism

13. Shortness Of Breath

Similar to other conditions, hyperthyroidism can cause shortness of breath to develop, as this condition causes the respiratory muscles to weaken and decrease in pulmonary function. Specifically, hyperthyroidism increases respiratory drive and can cause dyspnea on exertion, or shortness of breath. A patient may notice this sign whenever they become winded just from walking to the mailbox or climbing a flight of stairs, but many patients notice it is especially when they are at rest or during exercise. Specifically, the trachea becomes compressed, which can be positional, and can happen with nodular goiters (lumps on the neck) and thyroid cancer, but is also commonly seen in patients with hyperthyroidism, as the lungs do not respond properly to the increased metabolic rate caused by this condition.

14. Muscle Weakness, Especially in the Upper Arms and Thighs

Many people associate muscle fatigue with overexertion, but hyperthyroidism can quietly weaken large muscle groups over time—especially in the shoulders, upper arms, and thighs. Tasks like climbing stairs, lifting groceries, or even blow-drying your hair can suddenly feel unusually difficult. This is because the accelerated metabolism breaks down muscle tissue faster than the body can rebuild it. If you're losing muscle tone despite staying active, or feel unexpectedly shaky during everyday movements, your thyroid could be the hidden culprit.