Facts About The Human Body
31st August 2017

Heart Attacks and Strokes


LETS NOW look at one of the causes of High Blood Pressure. I’m starting at the beginning of every day with a condition called “Morning Hypertension” Research has shown that people can wake with high blood pressure and have an increased risk of suffering a Stroke or problems with their heart and blood vessels. This can affect some people who take blood pressure medication and have well controlled blood pressure at other times of the day.
Blood pressure is normally at its lowest during the hours we sleep, however, in the early morning hours through to late morning hours, the Hypothalamus is responsible for producing hormones that give you energy and make you alert ready for another day.
However, the hormones also raise your blood pressure. This increase in blood pressure puts people who are heavy drinkers, smokers and possibly some people who are already managing their blood pressure at risk. The risk is the possibility of a Stroke or Heart Attack in the morning, these conditions are attributed to “Morning Hypertension”...Read on for a lot more detail.

Why, we may ask, does blood pressure rise in the morning?

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Let me try to explain. It’s all to do with your “Body Clock” also called your “Biological Clock” In medical terms this is referred to as the “Circadian Rhythm” which tells our body when to sleep, when to rise and start another day, it also regulates other physiological body functions, even when you eat, all the above are related to the “Hypothalamus” and the main culprit called “Cortisol”(I’ve explained more about the Hypothalamus and Cortisol below) Your body clock is affected by daylight, temperature and is adjusted by external cues.
These cues are known as Zeitgebers which is an external time cue, mainly related to daylight, which synchronises your internal body clock with the day/night-time 24-hour cycle of the Earth’s rotating cycle.

The Hypothalamus produces Corticotrophin-Releasing Hormone

When triggered, the Hypothalamus produces Corticotrophin-Releasing Hormone, this travels to the Pituitary Gland which releases the Adrenocorticotropic Hormone, which alerts the Adrenal Glands which produce Corticosteroid Hormones. It’s the amount of Cortisol in the bloodstream that causes blood pressure to rise
The Hypothalamus is responsible for releasing or inhibiting hormones which, in turn start or stop the release of other hormones that have an impact on body functions that I’ve listed below.
  • Sleep
  • Body temperature
  • Thirst
  • Moods
  • Heart Rate
  • Blood Pressure (More below, Autonomic Nervous System)
The Hypothalamus is also a link between the Endocrine System and the body’s nervous system, and maintains the body’s internal balance known as Homeostasis, basically this ensures conditions in the body remain constant.

The Autonomic Nervous System

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The Autonomic Nervous System (Again regulated by the Hypothalamus) is influenced by Serum Cortisol and responsible for regulating some metabolic processes and blood pressure control through many mechanisms. It also regulates constriction and dilation of arteries which is a cause of high blood pressure, The Autonomic Nervous System can alter the Cardiac Output which in simple terms controls how much blood is pumped by the heart every minute, and again can influence blood pressure.
When triggered, the Hypothalamus produces a Corticotrophin-Releasing Hormone, this travels to the Pituitary Gland which releases the Adrenocorticotropic Hormone, which then alerts the Adrenal Glands which in-turn produces Corticosteroid Hormones. It’s the amount of Cortisol in the bloodstream that causes blood pressure to rise.
Cortisol in your bloodstream, increases by up to 54% within 30 minutes of waking and with some people be responsible for an increased Morning Blood Pressure, a blood test can check the Cortisol levels in your bloodstream. Under normal circumstances Cortisol levels drop and level out through the day.
A different time zone, or working shift hours has an impact on the body, there are many functions that are affected, the most common is sleep, changes are quickly detected by the body. You may recall I explained earlier in this section about the “Body Clock”, the 24-hour Circadian Rhythm cycle. Our body clock is synchronised with the Earth’s 24-hour cycle, mainly daylight. It can take several days for the body to adjust, if you’re on holiday, just when you start to adjust you return home, again taking several days to adjust. The pleasures of Jet-Lag.
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How to manage Cortisol is not easy, stress is one of the major causes that stops us getting a good night’s sleep. There are other conditions that cause high Cortisol levels, an overactive Adrenal Gland can cause Cushing’s Syndrome, which can be caused by Birth Control Pills (a hormonal contraception), long term use of Corticosteroids, a tumour, having a blood test will show Cortisol levels.
I’ve written in section (29) specific information about managing stress, if people can manage and reduce stress it will change Cortisol levels which will have an impact on:
  • Blood Pressure
  • Stroke
  • Heart
  • Arteries
  • Kidneys
  • Liver
  • And other organs
Conditions that can cause high Cortisol levels, include an overactive Adrenal Gland or Pituitary tumour, which in turn, can cause Cushing's Syndrome, as well as long term use of Corticosteriods (Prednisolone). A blood test can determine Cortisol levels.
If you have any concerns please discuss these with your Doctor or Health Professional.
Please click on any word that’s highlighted in blue to learn more. The information above is a long-winded way of saying, a good night’s sleep helps to manage morning blood pressure! However, I hope you found the information above interesting, explaining why, blood pressure can be higher in the morning.

Poor Sleep, not enough sleep, is a fundamental reason for abnormal Cortisol levels.

I’ve written more about this in the section about “Sleep”

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