Summarize this article:

Some people's symptoms are so mild, they may not realize it, but there are identifiable subtle signs of anemia. If you have only mild symptoms, schedule an appointment with your primary care provider. Mild symptoms include:  Fatigue and weakness since your muscles aren't getting enough oxygen. Shortness of breath, which is a sign your body needs more oxygen. You may only notice this when doing a physical activity, if your anemia is mild. Pale skin because you lack enough red blood cells to make up the red hue of your skin. Severe symptoms are signs that more of your organs are affected by the decreased oxygen in your bloodstream and are trying to circulate more blood through your body. These also indicate that your brain is being affected. If you have severe symptoms, see a doctor as quickly as you can. You may want to go to urgent care of the emergency room which can assess you sooner. Severe symptoms include:  Dizziness Headache Decrease in cognitive ability Fast heartbeat Your doctor will confirm anemia with a simple blood test called a Complete Blood Count, which determines the number of red blood cells your body has to see if they're too low. Your doctor can help you figure out if your anemia is acute or chronic. Chronic means it has been going on for a while and that you are in no immediate danger. Acute anemia means it is a new health problem and that the problem should be identified quickly to prevent progression to something more dangerous. Once a cause is determined, the correct treatment can be started. Your doctor may also order a body imaging scan (like a CT or MRI) or more advanced blood tests. If all tests are inconclusive, a bone marrow biopsy might need to be done.

Summary:
Identify symptoms of mild anemia. Recognize symptoms of severe anemia. See your doctor for a blood test.