The primary symptoms of hypotension are lightheadedness or dizziness. If the blood pressure is sufficiently low, fainting (syncope) may occur. Low blood pressure is sometimes associated with certain symptoms, many of which are related to causes rather than effects of hypotension: * chest pain * shortness of breath * irregular heartbeat * fever higher than 38.3 °C (101 °F) * headache * stiff neck * severe upper back pain * cough with sputum * prolonged diarrhea or vomiting * shakiness (shivering) * loss of appetite * dyspepsia (indigestion) * dysuria (painful urination) * acute, life-threatening allergic reaction * seizures * loss of consciousness * profound fatigue * temporary blurring or loss of vision * black tarry stools
symptom of Air embolism
symptom of Pulmonary embolism
symptoms of Air embolism
symptom of Myocardial infarction
symptom of Hypoxia 
symptom of Pulmonary heart disease
symptom of Heart failure
symptom of Aspiration pneumonia