Obesity-Effects on the Heart

Frequently Asked Questions

What is obesity?

Obesity is a condition in which you have too much body fat. You can use the body mass index (BMI) to see if you are obese. The BMI uses your height and weight to estimate how much fat is on your body. Obesity is classified as follows:

• Mild obesity: BMI of 30 to 34.9
• Moderate obesity: BMI of 35 to 39.9
• Morbid obesity: BMI of 40 or more

If your BMI is 25 to 29.9, you are considered to be overweight but not obese. You have a healthy weight if your BMI is 18.5 to 24.9.

What are the effects of obesity on the heart?

Obesity causes changes in the structure and function of the heart. This may happen even if you do not have other problems that affect the heart, such as high blood pressure or atherosclerosis.

The more you weigh, the more blood you have flowing through your body. The increased amount of blood means your heart has to pump more blood with each beat. This makes the heart work harder. It stretches and expands. The extra work makes the heart muscle thicker. The thicker the heart muscle gets, the harder it is for it to squeeze and relax. Over time, the heart may not be able to keep up with the load. You may then have heart failure.

Obese people often have high blood pressure. High blood pressure makes the heart work harder. The heart muscle gets even thicker because of the increased pressure. High blood pressure may be lowered by losing weight. Lowering your blood pressure and losing weight can also help your heart work better. You may also need to take blood pressure medicine or heart medicine to help.

Many obese people feel short of breath when they lie down because having a large abdomen keeps the lungs from having enough room to fill up with air when you breathe. Lying down may also make the thicker tissues in the throat and neck sag and that can keep the air from getting to the lungs. This temporarily interrupts breathing (apnea). If you do not breathe regularly, you have less oxygen in your blood. Less oxygen in your blood means less oxygen getting to your body, including your heart. This is not safe and may cause sudden death during sleep.

Low blood oxygen may also cause higher than normal blood pressure in the lungs. Blood is pumped from the right side of the heart into the lungs. High blood pressure in the lungs makes the right side of the heart work harder. If the right side of the heart cannot keep up with the work, you might feel short of breath or see swelling in your fingers or feet.

People who are obese often have high levels of blood lipids, which increase the risk of heart disease. Obesity also increases your risk of getting diabetes, and diabetes increases your risk of getting heart disease. How can I lower my risk of heart disease and heart attacks? Obesity by itself puts you at risk for heart disease even without high blood pressure, diabetes, or breathing problems. You can lower your risk of heart disease and other illnesses by staying at a healthy weight. If you already have heart disease, losing weight will lower your risk of other problems.

A plan for losing weight should include eating healthy foods, eating fewer calories, and being more physically active. Ask your healthcare provider to help you lose weight in a way that is safe, healthy, and effective. Also ask about the best way to increase your physical activity.