it can be due to high
blood pressure,
low blood pressure including bleeding disorders causing anemia, heart diseases like arrhythmias, attack, cardiomyopathy, medications like blood pressure drugs , antidepressants, metabolic disorders like hypoxia, hypoglycemia, dehydration. in women, internal bleeding or hemorrhage, anemia, infections, endocrine disease like thyroid, pituitary gland and adrenals, allergies may cause wheezing, low blood pressure, can trigger sinusitis and resulting dizziness.