This is a heart problem that some babies are born with. It's a narrowing of the aorta. That's the main vessel that carries blood from the heart to the body. This narrowing makes it hard for blood to pass through.
We don't know why an unborn child develops this condition. In some rare cases it develops later in life because of injury or other conditions.
Symptoms depend on the severity of the narrowing. A baby with a narrowed aorta may breathe fast, and may have problems eating. The baby may be sleepy, irritable and not very responsive. In older children, it can cause chest pain, shortness of breath, headaches and dizziness. It can cause cold legs or feet and leg cramps. It can cause nosebleeds and poor growth.
Treatment may involve medications and surgery. It's often surgically corrected soon after birth. Your healthcare provider can create a plan that's right for you.