Nitroglycerin has been a mainstay of treatment for many people with cardiovascular disease. Quick-acting nitroglycerin, in tablets or sprays, can halt an episode of chest pain, or angina, that occurs when the heart has to work harder to pump blood through blocked arteries. And, long-acting forms of the drug, such as nitroglycerin patches, are used to prevent angina. But research suggests that nitroglycerin patches may help treat a common problem unrelated to heart disease: tendon injury (tendinopathy). Studies have suggested that by using the patches right over the tendon with a lower dose than you would use if you had a cardiac problem, you actually improve the tendon blood flow, which may improve healing, says Susan Joy, MD, Director of Womens Sports Health at Cleveland Clinic.