• Barometric pressure is the weight of the atmosphere on the surface of the planet.puffy cloud image by chrisharvey from Fotolia.com
  
  Barometric pressure, otherwise called "atmospheric pressure," is basically the force, or pressure, that is exerted on the surface of the planet by the weight of the atmosphere above it. If you are lower on the surface, sea level or below, then you will feel a higher barometric pressure; if you are higher on the surface, on a mountain or an airplane, then you will feel a lower barometric pressure. Changes in the barometric pressure can have physical effects that are anywhere from mild to severe.
  
  

Ear Popping

• One of the more mild physical effects of barometric pressure is ear popping. Anyone who has driven on a steep hill or has been on an airplane has experienced ear popping, maybe even had to make his ears pop. Ear popping happens whenever there is a considerable change in barometric pressure, whether it be from high to low or the other way around. As the barometric pressure changes, the pressure within your ear has to balance itself with the pressure outside of your ear. The change in pressure within your ear causes the pop. Having your ears pop sounds worse than it is. Not having your ears pop will cause discomfort in your head, which is relieved by the ear popping. If your ears don't pop on their own, you should try to pop them either by yawning or by holding your nose and mouth closed while you blow out air from your lungs.
  
  

Headaches

• Changes in barometric pressure are accompanied by changes in oxygen levels. Higher barometric pressure comes with more oxygen and lower barometric pressure comes with less oxygen. Blood vessels in your head and brain either contract or expand to change the amount of blood flow in that area to compensate for the change in both pressure and oxygen levels, usually with higher barometric pressure. The change in blood flow will result in a headache. These barometric headaches can be mild, regular pressure headaches or severe, migraine or migraine-like headaches. Anti-inflammatory drugs (ibuprofen, for example) can help avoid or dull barometric headaches by reducing the inflammation of the blood vessels in your head, thereby reducing the blood flow problems. Though scientists are still not completely certain exactly why or how headaches occur, the previous belief is held as a likely explanation for barometric pressure headaches.
  
  

Heat Stress

• Higher barometric pressures are accompanied by higher levels of heat and humidity, which can increase a person's internal heat levels and cause heat stress or heat stroke. Different people feel heat stress differently, but the common symptoms include the inability to concentrate or complete mental tasks efficiently, the inability to complete physical tasks efficiently, dehydration, fatigue or exhaustion, and elevated heart rates. In severe cases, heat stress can cause heart attacks, strokes or even death.