By THÉRÈSE MARGOLIS

You take your car in for an oil change and a tire rotation every 3,000 miles. Come spring, you never fail to give your home a complete head-to-toe cleaning. And you are never late when it comes to presenting your annual tax declaration.

But when is the last time you had a thorough medical checkup?

Doctors say that everyone, regardless of age, should get a full medical examination once a year.

But according to the National Social Security Institute (IMSS), less than 10 percent of Mexicans comply with those guidelines.

There are a lot of reasons why people don’t get annual checkups. A lot of people simply don’t have access to medical care – only about 40 percent of the population is covered by private or public insurance. Others are afraid that their doctors will discover something wrong with their health and they feel that they would rather just not know about it.

But that’s a big mistake, and here’s why:

A checkup is intended to detect potential problems in their early stages. It is basically preventive medicine, which is the wave of the future in medical care. If you can catch a health concern in its early stages, you can treat it early, often simply through lifestyle changes, and avoid more costly and intrusive treatment later down the road.

One of the goals of doing any physical exam is to identify a problem ahead of time, and can be adapted to each patient’s needs.

An annual medical exam is a great screening tool, and it can be tailored to a patient’s personal history, age, sex and family history.

A thorough annual wellness visit should include a review of family history of disease, a basic mental-health screening and a discussion about lifestyle, as well as blood tests, urine tests, lung examinations, blood pressure checks, eye and ear exams, a colonoscopy and, in the case of women over 40, a Pap test and mammogram. Men over age 45 should also have a prostate exam.

Doctors find red flags in about 90 percent of patients who get medical checkups, but most of those warning signs are things that can be treated with relatively simple care, such as a change in diet or exercise. Left undetected and untreated, however, many of these conditions can lead to much more serious health problems and complications.

About 95 percent of patients will be able to resolve, or at least control, any new health problems that might show up as a result of an annual physical. Some 15 percent of patients will discover serious health concerns, but even those, if treated early, can be cared for to prevent more serious problems in the future.

Among the most important health ailments detected during annual medical exams are high blood pressure and diabetes.

People can go years with high blood pressure and the related damage to the kidneys, heart and eyes without any symptoms. The same holds true for diabetes.

Most chronic health conditions, like diabetes, don’t start overnight.

Consequently, if doctors discover that a patient’s blood sugar trend is creeping up, they can intervene and stop the patient from getting full.blown diabetes.

If you have a health concern or condition, you want to nip it in the bud.

Of course, it doesn’t do any good if you go in every year and get a checkup and then ignore the advice your health provider give you. You have to work in unison with your doctors.

Granted, getting an annual physical can be uncomfortable and time-consuming, usually demanding about eight hours and costing anywhere between 6,000 and 30,000 pesos.

But that is a lot less time and money than you would spend for a hospitalization. And you owe it to yourself and your family to take care of yourself.

We all know that if you take care of your car, it is going to last a lot longer. The same holds true with the human body, which is a very complex machine. And while you can always change your motor or transmission, it is not that easy to change your heart or lung.

Remember, there aren’t any spare parts department to replace organs that you misuse, so you need to take care of the originals.