**"Divers who take drugs to treat cardiovascular diseases often worry about the drugs' compatibility with diving. However, in most cases, it is the underlying condition and not the drug that should cause concern."** Some drugs may have side effects that preclude diving. Divers should be very familiar with the side effects of any drugs they take and should discuss them with their physician — and be sure their physician knows about their diving activities. A one-time clearance to dive does not preclude progression of a disease, so any changes in your health status should prompt another medical examination before you dive again.