The signs and symptoms of Grave's disease are determined not only by the disease itself but also by the consequent hyperthyroidism. The most common features of the disease are: exophtalmos, pretibial myxedema, increased heart rate, fatigue, muscular weakness and symptoms related to hyperthyroidism.
Due to the damage and fibrosis of the inferior rectus muscle, the patient will develop vertical diplopia, increased intraocular pressure and intermittent double vision. In the late stages of Grave's ophtalmopathy, exophtalmos occurs (leading to an impaired eye movement and optic neuropathy and optic nerve compression). The patient's visual acuity decreases, visual field defect, loss of color vision and afferent pupilary deffect occur. In this stage, any delay in treatment may lead to permanent blindness.
The goitre and the Graves' ophtalmopaty are the only symptoms directly determined by the disease. The other symptoms, caused by the increased levels of thyroid hormones are: hypertension, tachycardia, palpitations, fatigue, irritability, decreased concentration and diminished attention span. Dyspnea (shortness of breath), muscular weakness (especially in the muscles of the limbs), insomnia, and dry, brittle hair and nails are also common.

The hyperthyroidism has a marked impact on the patient's metabolism, leading to hyperglicemia, hypokalemia, weight gain and rhabdomylosis (muscle destruction determined by the increased energy consumption and by the depletion of the muscular deposits of glycogen).
The metabolic correlations established between the body's hormonal mechanisms will also affect the reproductive organs leading to amenorrhea or oligomenorrhea, infertility, difficulty conceiving and recurrent miscarriages. In men, gynecomastia may occur.