Does everyone know about the Silent Killer? High Blood Pressure? How high blood pressure can exist silently – without symptoms – for years until the sudden heart attack or stroke happens? There is also a silent killer of eyes – glaucoma.

Three million Americans have glaucoma – about 1 in a 100. Only half of them know they have it. And if human nature holds true, only half of them are doing something about it. That’s one in four. That means three out of four are facing limited or total loss of vision. Glaucoma is the silent killer of eyes.

Most people try to faithfully follow the owner's manual for maintaining their car: change the oil every 3000 miles, new oil filter every 50,000 miles, rotate the tires and check their pressure, check the transmission fluid, inspect the brake pads, fill the windshield wiper fluid. Faithful maintenance adds years to the car's life and prevents unwanted breakdowns at inconvenient times.

Sadly, many people don't do the same thing for the most valuable machine – their own body. Preventive maintenance of our bodies, along with regular checkups, can add years of life and prevent unwanted physical breakdowns, too.

Here's an owner’s manual of maintenance procedures and checkup schedules for the human body.

Preventive Maintenance: