Symptoms of a low hemoglobin count in the blood include fatigue, shortness of breath, a heart that races more than usual during exercise, and paleness in the skin and gums, explains Mayo Clinic. A doctor can order a laboratory test called a complete blood count to check hemoglobin levels.
A low hemoglobin count can be indicative of a wide variety of medical conditions, but it is not always associated with an underlying problem, notes Mayo Clinic. Some individuals naturally have blood counts that are lower than the generally accepted range, and pregnant women often show low hemoglobin counts on blood tests despite being healthy.
When a low blood count is related to a health problem, it may occur due to a condition in which the body makes fewer red blood cells than it needs, states Mayo Clinic. Examples include aplastic anemia, iron deficiency anemia, cancer, kidney disease and lead poisoning. Conversely, the culprit may be a condition that results in the body destroying red blood cells at a quicker pace than it can produce them, such as sickle cell anemia, vasculitis, thalassemia, an enlarged spleen or porphyria. Sometimes, the low blood count is the result of blood loss due to factors such as wounds, donating blood too frequently, nosebleeds or heavy menstruation.