Your blood pressure levels fluctuate throughout the day. They usually drop by 10 to 20 percent as you sleep, according to research published in the journal Hypertension. It typically increases within an hour of when you wake up.

A number of medical conditions and lifestyle factors can also cause increases in your blood pressure readings in the morning. A significant increase may be a sign of cardiovascular disease and warrants review from your doctor.

When you have obstructive or central sleep apnea, you experience pauses in your breathing while sleeping that can disrupt sleep quality and lead to numerous medical conditions.

According to the Hypertension article, sleep apnea can reduce the blood pressure drop that usually occurs when we sleep. This can lead to higher increases when you wake up in the morning.

Swings in blood pressure are twice as high in people with sleep apnea than those without, according to research published in Circulation Research. This can cause stress on your heart and cardiovascular system. If you suspect you have sleep apnea, contact your doctor.

Changes to your sleep schedule that are the result of your work or social schedule can also lead to increases in your morning blood pressure, says Sheldon G. Sheps, MD, professor emeritus of medicine at the Mayo Clinic College of Medicine in Rochester, Minnesota.

This can be because of social jet lag, or when your social obligations lead to an inconsistent sleep schedule or one that is not in tune with your biological clock. A study published in Hypertension Research says that social jet lag can lead to temporary high blood pressure in the mornings and also can be a long-term condition.

Shift work or working at night also has been linked to poor sleep patterns and high blood pressure in the morning, according to a study published in Nature.

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.

According to Mayo Clinic, medications that may increase blood pressure include:

• Antidepressants
• Birth control
• Decongestants
• Immunosuppressants
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Some herbal supplements, such as ginseng and licorice
• Stimulants, such as methylphenidate (Ritalin), which is used to treat attention deficit hyperactivity disorder (ADHD)

Caffeine can cause a temporary spike in blood pressure, Mayo Clinic says, which means a morning cup of coffee can increase morning blood pressure levels. Reducing caffeine intake can prevent temporary increases in morning blood pressure readings.

Caffeine itself does not cause long-term high blood pressure, however, Mayo Clinic says.

But using and smoking tobacco can increase your risk of high blood pressure, according to the American Heart Association. The nicotine in tobacco products causes the blood vessels to constrict. This forces the heart to work harder to pump blood, increasing blood pressure. 

Numerous health organizations recommend stopping tobacco use to reduce the risk of developing high blood pressure, according to a study published in the American Journal of Medicine.

High blood pressure itself, also known as hypertension, can also lead to abnormally high blood pressure levels when you wake up in the morning.

If hypertension is not managed, it can increase the risk of stroke, heart attack, kidney disease, and other serious medical conditions. 

If you take hypertension medication at night, it may wear off by morning, leading to high blood pressure levels, according to research published in Hypertension.

Tumors in the adrenal glands, such as pheochromocytoma, can cause an overproduction of the hormones that affect heart rate and blood pressure, raising blood pressure. 

Although these tumors are rare, according to Johns Hopkins Medicine, they may cause high blood pressure and other symptoms that include:

• Anxiety 
• Fast pulse
• Headache
• Nausea and vomiting
• Shaking
• Sweating

These symptoms may be the result of other issues as well. If you’re experiencing them, contact your doctor.