Pulmonary edema cardiac arrest due to hypoxia. It is a cardinal feature of congestive heart failure. The term edema is from the Greek (oídēma, "swelling"), from οἰδέω (oidéō, "I swell"). The most common symptom of pulmonary edema is difficulty breathing, but may include other symptoms such as coughing up blood (classically seen as pink, frothy sputum), excessive sweating, anxiety, and pale skin. Shortness of breath can manifest as orthopnea (inability to lie down flat due to breathlessness) and/or paroxysmal nocturnal dyspnea (episodes of severe sudden breathlessness at night). These are common presenting symptoms of chronic pulmonary edema due to left ventricular failure.
Cerebral edema such as ischemic stroke, cancer, or brain inflammation due to meningitis or encephalitis. Vasogenic edema caused by amyloid-modifying treatments, such as monoclonal antibodies, is known as ARIA-E (amyloid-related imaging abnormalities edema). The blood–brain barrier (BBB) or the blood–cerebrospinal fluid (CSF) barrier may break down, allowing fluid to accumulate in the brain's extracellular space. One manifestation of this is P.R.E.S., or Posterior Reversible Encephalopathy Syndrome. Altered metabolism may cause brain cells to retain water, and dilution of the blood plasma may cause excess water to move into brain cells. Fast travel to high altitude without proper acclimatization can cause high-altitude cerebral