DNA is a double helix formed by base pairs attached to a sugar-phosphate backbone. DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms.Nearly every cell in a personâs body has the same DNA.Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).NA is a double helix formed by base pairs attached to a sugar-phosphate backbone. DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms.
1 In particular, blood pressure lowering medications may cause faintness if they lower your blood pressure too much. 2  Anxiety disorders. 3  Certain anxiety disorders may cause lightheadedness or a woozy feeling often referred to as dizziness.
When to see a doctor. Make an appointment with your doctor if you're feeling fatigued for unexplained reasons. Some anemias, such as iron deficiency anemia or vitamin B-12 deficiency, are common. Fatigue has many causes besides anemia, so don't assume that if you're tired you must be anemic. Some people learn that their hemoglobin is low, which indicates anemia, when they go to donate blood. If you're told that you can't donate blood because of low hemoglobin, make an appointment with your doctor.