overdraft facility. A credit agreement made with a financial institution that permits an account holder to use or withdraw more than they have in their account, without exceeding a specified maximum negative balance.
Without treatment, moyamoya disease can be fatal. Left untreated, individuals with the disease will experience mental decline and multiple strokes due to the narrowing of the arteries. Related: 1  Learn the signs and symptoms of a stroke.
Severe hyperthyroidism, called thyrotoxic crisis (thyroid storm), may be life-threatening because of its effects on the heart and brain. It often occurs in people who are untreated or are receiving inadequate treatment for thyroid problems. A severe infection can also cause a thyrotoxic crisis.