Preeclampsia sometimes develops without any symptoms. High blood pressure may develop slowly, but more commonly it has a sudden onset. Monitoring your blood pressure is an important part of prenatal care because the first sign of preeclampsia is commonly a rise in blood pressure. Blood pressure that is 140/90 millimeters of mercury (mm Hg) or greater — documented on two occasions, at least four hours apart — is abnormal.
Other signs and symptoms of preeclampsia may include:
Excess protein in your urine (proteinuria) or additional signs of kidney problems
Severe headaches
Changes in vision, including temporary loss of vision, blurred vision or light sensitivity
Upper abdominal pain, usually under your ribs on the right side
Nausea or vomiting
Decreased urine output
Decreased levels of platelets in your blood (thrombocytopenia)
Impaired liver function
Shortness of breath, caused by fluid in your lungs
Sudden weight gain and swelling (edema) — particularly in your face and hands — often accompanies preeclampsia. But these things also occur in many normal pregnancies, so they're not considered reliable signs of preeclampsia.
When to see a doctor
Make sure you attend your prenatal visits so that your care provider can monitor your blood pressure. Contact your doctor immediately or go to an emergency room if you have severe headaches, blurred vision, severe pain in your abdomen or severe shortness of breath.
Because headaches, nausea, and aches and pains are common pregnancy complaints, it's difficult to know when new symptoms are simply part of being pregnant and when they may indicate a serious problem — especially if it's your first pregnancy. If you're concerned about your symptoms, contact your doctor.