The body undergoes many changes during and after pregnancy. Even if your pregnancy was without complications, there's still a chance issues may develop after baby arrives. A recent study in the journal Hypertension shows that 1 in 10 healthy women develop high blood pressure after giving birth, known as postpartum hypertension.

So what causes postpartum hypertension, and what can you do?

How blood pressure changes during pregnancy and after giving birth

"Blood pressure tends to be at its lowest between 16-20 weeks, and that's due to physiological changes in pregnancy, such as blood volume doubling," says Dr. Mae Borchardt, an OB-GYN with Houston Methodist. "Towards the end of pregnancy, it tends to naturally increase to your body's pre-pregnancy blood pressure."

New mothers can expect their blood pressure to peak three to six days after delivery, whether or not they experienced high blood pressure during pregnancy. This peak can be caused by pain; medicines such as non-steroidal anti-inflammatory drugs (NSAIDs); extra fluids given postpartum; or your blood vessels contracting back to their pre-pregnancy levels.

What is postpartum hypertension?

High blood pressure is considered postpartum hypertension when the systolic pressure (the top number) is 140 mm Hg, and the diastolic pressure (the bottom number) is 90 mm Hg or higher.

Developing hypertension in the postpartum period is slightly less common than during pregnancy. A hypertension diagnosis happens in about 11% of all pregnancies, according to Dr. Borchardt.

High blood pressure is associated with early heart disease, seizures, stroke, and even death.

Postpartum hypertension symptoms

Mild to moderate hypertension can be silent, without any symptoms. So for new mothers experiencing any high blood pressure symptoms, you'll want to talk to your doctor. Depending on your blood pressure readings and any symptoms, you may require treatment.

"Oftentimes with mild postpartum hypertension, there's nothing additional we need to do," Dr. Borchardt said. "We just know she's at higher risk for blood pressure disorders in her next pregnancy and later in life. But if someone is running high blood pressures after delivery, we will bring them in for an evaluation to rule out preeclampsia."

If you have high blood pressure postpartum, you'll want to call your doctor if you notice that you have:

• Pain in your jaw, arm, neck or back
• Clammy, cold sweats
• Dry cough
• Heart palpitations
• Lightheadedness
• Nausea
• Severe headache
• Severe fatigue
• Sudden weight gain
• Swollen ankles or feet

Seek emergency care immediately if you experience:

• Chest pain
• Fainting
• Shortness of breath
• Vision issues

Postpartum hypertension vs. postpartum preeclampsia

Postpartum hypertension differs from postpartum preeclampsia — a condition where blood pressure is dangerously high and can cause seizures, called eclampsia.

Traditionally, preeclampsia was diagnosed when women had blood pressure at 140/90 or higher, with protein in the urine. The American College of Obstetricians and Gynecologists expanded the definition of preeclampsia -- it can be diagnosed with or without protein in the urine. Women can be diagnosed with preeclampsia when experiencing different symptoms along with high blood pressure.

"The criteria for preeclampsia have become more overlapping," Dr. Borchardt said.

Postpartum preeclampsia is a medical emergency and needs treatment immediately. Most cases of postpartum preeclampsia happen 48 hours after giving birth. Signs of postpartum preeclampsia include:

• Blood pressure of 140/90 or higher
• Changes in your vision, including blurry vision, seeing spots or sparkles
• Severe headache that does not go away
• Stomach pain, nausea, or vomiting
• Sudden weight gain
• Swelling in the hands or face
• Trouble urinating
• Trouble breathing or shortness of breath

Who is at risk for postpartum hypertension?

Any new mother can develop high blood pressure during or after pregnancy. There is often a genetic component to developing hypertension during pregnancy or postpartum, according to Dr. Borchardt.

Women who experience gestational hypertension or preeclampsia during a current or previous pregnancy have the highest risk. Other risk factors can include:

• Having a chronic condition before your pregnancy, such as diabetes or high blood pressure
• Having a multiple pregnancy (twins, triplets, quadruplets or more)
• Having a cesarean section (C-section)
• Being a woman of color
• Being underweight or overweight
• Having your first pregnancy over age 35
• Having a history of smoking or being a current smoker

How is postpartum hypertension treated?

Treatment will depend on symptoms and current blood pressure. For women with mild hypertension, no treatment may be needed. Medicines may be given intravenously if blood pressure is dangerously high. Oral medications may be provided to treat elevated blood pressure. You may also be asked to monitor your blood pressure at home through an ambulatory blood pressure monitoring device or by keeping a log.

Can you breastfeed with postpartum hypertension?

Breastfeeding is considered the best nutrition source available for newborns, offering many protective health benefits. If possible, the American Academy of Pediatrics recommends breastfeeding for the first six months. Breastfeeding offers mothers some health benefits, too.

Breastfeeding has been shown to help lower blood pressure in the postpartum period and later in life, according to the American Heart Association. Breastfeeding women may also be at lower risk for high cholesterol, diabetes and heart disease later in life. Breastfeeding also burns a lot of calories, which can help women lose pregnancy-related weight that helps to fuel fetal growth.

Women with postpartum hypertension need not worry. Medications used to treat high blood pressure during and after pregnancy are safe to use while breastfeeding.

Can you prevent postpartum high blood pressure?

"Talk to your doctor about your individual risks," Dr. Borchardt says. "But living a healthy lifestyle and exercising can help lower your risk overall."

To help protect against preeclampsia and hypertension during pregnancy, your doctor may prescribe low-dose aspirin in the second trimester if you're at higher risk.