Your nose is a first line of defense against the bacteria and viruses before they enter your airways and lungs so it requires a certain level of humidity to work properly. Therefore, if your nose is dried out, obviously it fails its function in preventing the germs from entering your body. There are a number of causes that lead to dryness in the nose. Extremely hot or dry climates (as well as air conditioning) can result in your nose losing moisture and drying out. Dry nose is also a common side effect of certain medications, such as some antihistamines and decongestants. Nasal sprays that are used to relieve a nasal congestion can cause a dried out nose or rebound effect when they are overused. Upper respiratory infection (i.e., rhinitis) and hormonal changes experienced by women entering menopause also cause a drying out of mucous membranes in the nasal tissues. Although dry nose is rarely a sign of a serious medical condition, you should seek prompt medical care if your dry nose is persistent to rule out an underlying disease. Sjogren's syndrome is an autoimmune disease characterized by the drying out of mucous membranes throughout the body that may also result in dry nose. Dry nose accompanied by nose bleeds may be an indicator of high blood pressure
. I would suggest a visit with a primary care physician
or ENT to determine the actual cause of your dry nose so that you can be treated properly.