Each of the heart’s four chambers is a blood-filled space surrounded by a wall of heart muscle. These four chambers work as four separate pumps, pushing blood around your body.

Most people are born with a small, but perfectly shaped heart that grows in proportion to the rest of the body. Once you stop growing, your heart stops growing.

But different conditions can cause the heart to get larger after the rest of your body stops growing.

This can happen if:

• The muscular wall of one or more of the chambers thickens. When this happens, it’s usually the wall of the left ventricle, the main chamber of the heart.
• The inside space of the heart chambers expand.

Sometimes both of these things happen to make the heart get bigger.

Conditions that cause the heart to get larger include:

• High blood pressure. The left ventricle must work harder because it’s trying to push blood against a higher pressure. Over time, the extra workload thickens the left ventricle wall.
• A leaky heart valve. When a valve leaks, some of the blood that has just been pumped out slips back into the chamber. The backflow can cause the inside space of the chamber to get larger because it’s forced to hold more blood than it was designed to.
• Inflammation of the heart muscle (myocarditis). A viral infection or problem with the immune system can inflame the heart muscle cells. The walls can get thicker and weaker. Weaker heart walls allow the inside space of the heart chambers to get wider.

Your doctor will review your medical history, examine you and run some tests to figure out the cause. With treatment, there’s a good chance your heart will stop growing.