The most common reasons for feeling tired and dizzy are malnutrition, dehydration, and the common cold or influenza. Anemia may also be responsible. Although the main symptoms of the common cold are usually a runny nose, sneezing, and nasal congestion, the person affected may also feel tired and dizzy. Dizziness and fatigue are also very common symptoms of the flu, which is a virus similar to but more severe than the common cold. Lastly, malnutrition and dehydration happen when the body is not getting the foods and fluids that it needs to thrive, so a person with unhealthy eating habits or someone lacking the resources to keep himself healthy will likely feel fatigue and dizziness as time goes on.
Influenza and the common cold are common viruses that are both capable of making a person feel dizzy and tired. Besides a noticeable lack of energy and dizziness, the flu generally presents with symptoms such as vomiting, fever, and body aches. The common cold is less severe, with symptoms such as a cough, runny nose, and sneezing. Influenza is commonly mistaken for the common cold at first, but it is typically more severe and can lead to pneumonia, which is especially fatal in the young and elderly. Dizziness and fatigue caused by the common cold and influenza subside as the person recovers from the virus.
A shortage of bodily fluids, or dehydration, is another common reason for feeling tired and dizzy. Some common reasons for dehydration include the lack of proper water consumption, physical activity, and vomiting. Drinks containing alcohol and caffeine can significantly contribute to dehydration, especially when consumed in high quantities. The consumption of such beverages may also lead to the drinker thinking that he or she has been consuming normal amounts of hydrating fluids, and thus not considering dehydration as a possibility for the cause of feelings of fatigue and dizziness.
Not consuming a balanced diet complete with a wide variety of vitamins and minerals can contribute to feelings of fatigue and dizziness. Many vitamins, if not consumed in proper amounts, can cause negative reactions. Feeling tired and dizzy may also be caused by low blood sugar, which in some cases can be fixed by the proper type of snack.
Another cause of fatigue and dizziness is anemia, which literally means lack of blood. People diagnosed with anemia are suffering from a decrease in red blood cells, or their blood has a below-average amount of iron-containing proteins that deliver oxygen. Either way, the organs end up getting less oxygen than they need, which in turn can make a person feel weak, tired, and dizzy. In fact, feeling a general weakness and tiredness is one of the most reported signs of anemia.