Other and unspecified disorders of circulatory system (I99)

Browse all the diagnosis codes used for other and unspecified disorders of circulatory system (i99). For easy navigation, the diagnosis codes are sorted in alphabetical order and grouped by sections. Each section is clearly marked with its description, and the corresponding three-digit code range. This format makes it simple to browse diagnosis codes in this chapter or section and find what you're looking for. We've also added green checkmark icons to label billable codes, and red warning icons for non-billable ones. This makes it easy to identify which codes can be billed.

Clinical Information

Brain Ischemia - Localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. This frequently occurs in conjunction with brain hypoxia (HYPOXIA, BRAIN). Prolonged ischemia is associated with BRAIN INFARCTION.

Chronic Limb-Threatening Ischemia - A severe form of peripheral artery disease in which a hypoperfusion of the BLOOD through an organ or tissue is caused by occlusion of peripheral arterial vessels. It is associated with the presence of chronic ischemic rest pain, ulceration or GANGRENE.

Cold Ischemia - The chilling of a tissue or organ during decreased BLOOD perfusion or in the absence of blood supply. Cold ischemia time during ORGAN TRANSPLANTATION begins when the organ is cooled with a cold perfusion solution after ORGAN PROCUREMENT surgery, and ends after the tissue reaches physiological temperature during implantation procedures.

Hypoxia-Ischemia, Brain - A disorder characterized by a reduction of oxygen in the blood combined with reduced blood flow (ISCHEMIA) to the brain from a localized obstruction of a cerebral artery or from systemic hypoperfusion. Prolonged hypoxia-ischemia is associated with ISCHEMIC ATTACK, TRANSIENT; BRAIN INFARCTION; BRAIN EDEMA; COMA; and other conditions.

Ischemia - A hypoperfusion of the BLOOD through an organ or tissue caused by a PATHOLOGIC CONSTRICTION or obstruction of its BLOOD VESSELS, or an absence of BLOOD CIRCULATION.

Ischemic Attack, Transient - Brief reversible episodes of focal, nonconvulsive ischemic dysfunction of the brain having a duration of less than 24 hours, and usually less than one hour, caused by transient thrombotic or embolic blood vessel occlusion or stenosis. Events may be classified by arterial distribution, temporal pattern, or etiology (e.g., embolic vs. thrombotic). (From Adams et al., Principles of Neurology, 6th ed, pp814-6)

Mesenteric Ischemia - Ischemic tissue injury produced by insufficient perfusion of intestinal tissue by the MESENTERIC CIRCULATION (i.e., CELIAC ARTERY; SUPERIOR MESENTERIC ARTERY; INFERERIOR MESENTERIC ARTERY; and MESENTERIC VEINS). It can progress from ISCHEMIA; EDEMA; and GANGRENE of the bowel wall to PERITONITIS and cardiovascular collapse.

Myocardial Ischemia - A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (CORONARY ARTERY DISEASE), to obstruction by a thrombus (CORONARY THROMBOSIS), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Severe interruption of the blood supply to the myocardial tissue may result in necrosis of cardiac muscle (MYOCARDIAL INFARCTION).

Optic Neuropathy, Ischemic - Ischemic injury to the OPTIC NERVE which usually affects the OPTIC DISK (optic neuropathy, anterior ischemic) and less frequently the retrobulbar portion of the nerve (optic neuropathy, posterior ischemic). The injury results from occlusion of arterial blood supply which may result from TEMPORAL ARTERITIS; ATHEROSCLEROSIS; COLLAGEN DISEASES; EMBOLISM; DIABETES MELLITUS; and other conditions. The disease primarily occurs in the sixth decade or later and presents with the sudden onset of painless and usually severe monocular visual loss. Anterior ischemic optic neuropathy also features optic disk edema with microhemorrhages. The optic disk appears normal in posterior ischemic optic neuropathy. (Glaser, Neuro-Ophthalmology, 2nd ed, p135)

Reperfusion Injury - Adverse functional, metabolic, or structural changes in tissues that result from the restoration of blood flow to the tissue (REPERFUSION) following ISCHEMIA.

Spinal Cord Ischemia - Reduced blood flow to the spinal cord which is supplied by the anterior spinal artery and the paired posterior spinal arteries. This condition may be associated with ARTERIOSCLEROSIS, trauma, emboli, diseases of the aorta, and other disorders. Prolonged ischemia may lead to INFARCTION of spinal cord tissue.

Vascular Calcification - Deposition of calcium into the blood vessel structures. Excessive calcification of the vessels is associated with ATHEROSCLEROTIC PLAQUES formation particularly after MYOCARDIAL INFARCTION (see MONCKEBERG MEDIAL CALCIFIC SCLEROSIS) and chronic kidney diseases which in turn increase VASCULAR STIFFNESS.

Vertebrobasilar Insufficiency - Localized or diffuse reduction in blood flow through the vertebrobasilar arterial system, which supplies the BRAIN STEM; CEREBELLUM; OCCIPITAL LOBE; medial TEMPORAL LOBE; and THALAMUS. Characteristic clinical features include SYNCOPE; lightheadedness; visual disturbances; and VERTIGO. BRAIN STEM INFARCTIONS or other BRAIN INFARCTION may be associated.

Visceral Pain - Pain originating from internal organs (VISCERA) associated with autonomic phenomena (PALLOR; SWEATING; NAUSEA; and VOMITING). It often becomes a REFERRED PAIN.

Warm Ischemia - A tissue or organ remaining at physiological temperature during decreased BLOOD perfusion or in the absence of blood supply. During ORGAN TRANSPLANTATION it begins when the organ reaches physiological temperature before the completion of SURGICAL ANASTOMOSIS and ends with reestablishment of the BLOOD CIRCULATION through the tissue.