Blood pressure measures how hard the heart is working, and how healthy the arteries are. There are two numbers in each blood pressure measurement:
- The first (top) number is the systolic blood pressure, which measures the force of blood released when the heart beats.
- The second (bottom) number is the diastolic pressure, which measures the pressure in the arteries when the heart is at rest.
Blood pressure measurements are written this way: 120/80. One or both of these numbers can be too high.
Several factors affect blood pressure, including:
- The health of the heart and blood vessels
- The health of the kidneys
High blood pressure in infants may be due to kidney or heart disease that is present at birth (congenital). Common examples include:
- Coarctation of the aorta
- Patent ductus arteriosus
- Bronchopulmonary dysplasia
- Renal artery stenosis
In newborn babies, high blood pressure is often caused by a blood clot in a kidney blood vessel, a complication of having an umbilical catheter.
Other causes of high blood pressure in infants may include:
- Certain medicines
- Exposure to illegal drugs such as cocaine
- Certain tumors
- Inherited conditions (problems that run in families)
- Thyroid problems
Blood pressure rises as the baby grows. The average blood pressure in a newborn is 64/41. The average blood pressure in a child ages 1 month - 2 years is 95/58. Some variations in these numbers are normal and are not cause for concern.