Static Electricity

• When humidity decreases, static electricity increases. According to the site Science Made Easy, dry air acts as an insulator. Objects such as metal, synthetic fabric and our bodies act as conductors. When air is dry, electrons build up on conductors until they can transfer to another conductor. For example, if we brush our hair in a dry room, our hair will build up a charge. If we then touch a metal doorknob, we get a shock, the result of a transfer of electrons from one conductor to another. In homes with ideal humidity levels, water molecules in the air act as the conductors, bond with electrons and static electricity is lessened.
  
  

Itchy Skin

• Low humidity is one factor that contributes to dry, itchy skin. According to Cleveland Clinic, dry skin if untreated can affect sleep, moods and can lead to a dermatitis (inflamed red rash) or eczema (chronic inflamed, cracked red skin). To treat dry, itchy skin, reduce the number of showers you take. Use a non-soap cleanser, one that can be left on the skin as an emollient layer. At night, take an antihistamine to reduce itching and improve sleeping comfort. Finally, add a humidifier to your bedroom, or if you afford it, one that connects to the home heating system.
  
  

Sore Throat

• Chronic sore throats that linger can be caused by irritants such as low humidity. It also causes sinus congestion, a condition that leads to mouth breathing, an additional sore irritant. Though this type of sore throat isn't dangerous, dry mucous membranes in the throat and nasal passages may predispose your body to viral or bacterial infections such as the common cold, strep throat and sinusitis.
  
  

Sinus Infections

• Low humidity dries out mucus membranes. It causes congestion, the result of swollen nasal membranes, a thickening of mucus and post-nasal drip. When mucus thickens, it becomes less effective at trapping allergens and bacteria. As a result, bacteria can breed within the sinus cavities into full-blown sinus infections. Treatment for a sinus infection usually includes antibiotics, a saline nasal wash and humidified air.
  
  

Cracks in Furniture

• Though not related to our health, low humidity affects our home. Over time, dry air saps the moisture from wood furniture and floors. Cracks may develop in varnish finishes, wood planks can shrink and seams in furniture may separate. The best prevention against furniture damage is to use a cool-mist humidifier and to purchase a hygrometer, a device that measures air humidity.