Hyperthyroidism, whether caused by Graves' disease or another condition, produces consistent signs and symptoms that affect every part of your body. The major abnormalities are described in the following sections, grouped according to the organ system of the body that is affected.
The body generally
Hyperthyroidism can cause your body temperature to be persistently high. You may lose weight despite an increased appetite. The weight loss is due to the loss of lean body tissue like muscle, not due to a loss of fat. In rare cases, a patient gains weight because she is eating so many calories. Hyperthyroidism can cause you to feel weak. You may feel lymph glands all over your body, because Graves' disease is an autoimmune disease and the lymph system is a key player in autoimmunity. Your tonsils, which are part of the lymph system, are also enlarged.
There are other possible reasons for the enlargement of lymph glands that are more serious than Graves' disease, so if you experience this, see your doctor.
The thyroid
When Graves' disease is the cause of hyperthyroidism, your thyroid is enlarged in a symmetrical way and the entire gland is firm. When a single overactive nodule (a bump on your thyroid) is to blame for hyperthyroidism, that nodule is large, but it often causes the rest of the gland to shrink. When a multinodular goiter is responsible, you can feel many lumps and bumps on your thyroid.
If you put your hand over an enlarged thyroid, you can often feel a buzz that is called a thrill and results from the great increase in blood flow in the overactive thyroid. You can hear the thrill with a stethoscope; the sound is called a bruit.
The skin and hair
Hyperthyroidism can cause your hands to feel warm and moist, and they may appear red. You may experience a loss of skin pigmentation (a condition called vitiligo) in places, which is another sign of autoimmunity. Other areas of your skin may appear darker. Your hair may be fine, straight, and unable to hold a curl.
The heart
Hyperthyroidism can cause a rapid pulse, which you feel as heart palpitations. The first sign of Graves' disease is sometimes atrial fibrillation, an irregular heart rhythm. If a patient is older and already has heart disease, hyperthyroidism can induce heart failure, or heart pain (angina) may appear or be made worse because the heart beats too rapidly. You may experience shortness of breath.
The nervous system and muscles
If you have hyperthyroidism, your fingers have a fine tremor when you hold your hands out. The loss of muscle tissue leads to weakness. Your reflexes are increased; some patients can't sit still. Basically, if you are hyperthyroid, most likely you're nervous, you don't sleep as much as you used to, and you have rapidly changing emotions, from exhilaration to depression.
The reproductive system
Hyperthyroidism can cause a decrease in fertility because it interferes with ovulation. Menstrual flow is decreased as well and may cease.
The stomach and intestines
If you are hyperthyroid, food moves more quickly through your intestines than it used to, and you have more frequent bowel movements or even diarrhea. You may experience nausea and vomiting.
The urinary system
As more blood flows, your kidneys filter more, and more urine is produced so you go to the bathroom more frequently. In turn, you feel more thirsty than usual.
The eyes
Any form of hyperthyroidism results in reversible changes to the eyes. Your upper eyelids may be pulled up higher so more of the white above the pupil is seen, which makes it appear as if you're staring and pop-eyed. When you are asked to look down, your upper eyelid may not follow your eye, which exposes even more white. This is called lid lag.
Graves' disease can cause more serious eye problems.