There are certain times that physical symptoms such as feeling cold or feeling fatigue have an internal cause. These symptoms occur for all age groups and for both males and females. Even after rest or in warmer weather, symptoms of cold and fatigue do not subside. The causes of these symptoms might be due to iron-deficiency anemia, H1N1 flu, or hypothyroidism, which is also referred to as under-active thyroid.
Iron Deficiency Anemia
Iron-deficiency anemia is a condition of the blood where patients are often low in hemoglobin, red blood cells or iron. The symptoms of anemia include feeling colder than others, fatigue, headache and sometimes dizziness. The causes of feeling cold and fatigue due to iron-deficiency anemia include a diet that does not contain enough iron for the blood to build sufficient hemoglobin or a need for additional iron, such as during pregnancy. The Cleveland Clinic advises that anemia is also caused by "Blood loss (caused within the body by ulcers, some cancers, and other conditions; and, in women, during monthly periods)." Iron-deficiency anemia and feelings of cold and fatigue are often not permanent if iron is properly introduced into the blood stream.
H1N1 Flu
Although it is a common notion that the flu causes fevers, it is not always the case. The strain of flu referred to as H1N1 Flu, also known as the swine flu, causes chills and fatigue. Because this particular flu does not present a fever, it is difficult to diagnose and oftentimes, people may be unaware of the infection. From information on H1N1 Flu from the Mayo Clinic, "Diagnosing H1N1 flu may be a little trickier in people who don't develop a fever. And it may be more difficult for these people to know when it's safe to go back to work or school."
Hypothyroidism
Hypothyroidism is also referred to as under-active thyroid. It is a condition caused in children and adults when the thyroid does not make enough hormones. From the Virtual Pediatric Hospital, hypothyroidism in infants cause a low temperature and a general slowing of body processes, including everyday functions. In adults, an under-active thyroid causes the feeling of staying cold and fatigue all the time.
