Causes of High Blood Pressure in the Morning

Blood pressure levels fluctuate throughout the day, with the lowest readings usually occurring when a person is asleep. Once a person rises in the morning, blood pressure levels begin to increase. Several medical conditions and lifestyle factors can also cause increases in morning blood pressure readings. Controlling these factors can help reduce blood pressure levels in the early hours.

Sleep apnea is a medical condition characterized by heavy snoring and pauses in respiration during the night. Researchers at Johns Hopkins School of Public Health conducted a study that found a link between sleep apnea and increased blood pressure. The results of the study, which were published in the April 12, 2000 issue of the "Journal of the American Medical Association," indicate that people who experience the highest number of pauses in breathing while asleep have twice the normal risk of developing high blood pressure.

Some medications can cause temporary increases in blood pressure. If these medications are taken in the morning, blood pressure can increase early in the day and fall in the evening. Corticosteroids, which are used to treat asthma, autoimmune diseases, skin problems and severe allergies, are known to cause increases in blood pressure. Decongestants, particularly those containing pseudoephedrine, also lead to temporary increases in blood pressure levels.

According to Dr. Sheldon Sheps of the Mayo Clinic, a person's work schedule can have an impact on blood pressure levels in the morning. A study conducted by Frank Scheer and his colleagues at Brigham and Women's Hospital and Harvard University validates this claim. During Scheer's study, participants adjusted their normal daytime routines to reflect the routine of someone who works an unusual shift. In addition to the development of pre-diabetes, decreased insulin sensitivity and impaired glucose tolerance, some participants experienced increased daytime blood pressure levels. The results of this study were published in the March 2, 2009 online issue of "Proceedings of the National Academy of Sciences."

Hypertension, also known as high blood pressure, is diagnosed when someone has several high blood pressure readings. This condition can increase the risk for strokes, heart attacks, kidney disease and other serious medical conditions. If blood pressure medication is taken at night, it may wear off by morning, leading to high blood pressure levels. If hypertension is not controlled, morning blood pressure readings may also be abnormally high.

The adrenal glands produce hormones that affect heart rate, blood flow and blood pressure. Epinephrine increases the heart rate and relaxes the smooth muscles of the body. Norepinephrine does not have as much of an effect on the heart rate and smooth muscles, but increases blood pressure. Adrenal tumors can cause an overproduction of these hormones, raising blood pressure. If norepinephrine is released in the morning, morning increases in blood pressure may be noted.

Tobacco and caffeine use play a role in increased blood pressure levels. Tobacco use is one of the major risk factors for high blood pressure, because the nicotine in tobacco products causes the blood vessels to constrict. This forces the heart to work harder to pump blood, increasing blood pressure. The American Academy of Family Physicians recommends stopping tobacco use to greatly reduce the risk of developing high blood pressure. Caffeine can also cause temporary spikes in blood pressure, which means that a morning cup of coffee can cause an increase in morning blood pressure levels. The risk seems to be greater in people who already have hypertension and those who do not drink caffeine regularly. Reducing caffeine intake can prevent temporary increases in morning blood pressure readings.