Category Archives: Self checks

Thyroid problems and blood pressure connection

Thyroid problems and blood pressure connection

Blood pressure can be affected by many factors. Thyroid hormone imbalances affect blood pressure greatly. In my previous post, I had talked about body temperature being indicative of thyroid dysfunction. Blood pressure is also a strong indicator of thyroid function for people with thyroid hormonal imbalances. It is important to observe body signals as they are number one indicators that something is not right with thyroid hormones for people with thyroid issues.

I remember one day driving to my doctor for a check- up visit in heavy traffic while munching on chocolate coated coffee beans. I was almost late and when I saw my doctor, I was a bit flustered. I had a busy, stressful day. During a consultation with my doctor, she measured my blood pressure and it was through the roof. I do not know about you but I always get a bit nervous when my doctor is about to measure my blood pressure despite trying to stay calm and breathing deeply. Just feeling stressed, uncomfortable can raise blood pressure by itself. Blood pressure often fluctuates throughout the day. However it is not the temporary spikes of blood pressure we have to worry about but the sustained, chronic high blood pressure. Some people are not aware of their raised blood pressure. Blood pressure problems may be silent. For me, headaches, general tension, pins and needles in my arms and whooshing sound in my ears in the evening points to a possible blood pressure problem and possible hormonal imbalance. During my consultation that day, I had found out that my TSH value was 0.22, too low for me. I operate best at value of 1.7 so the dose of my hormonal replacement was slightly reduced and blood pressure came down. I also stopped drinking coffee and went to have decaffeinated variety and no more chocolate coated coffee beans!

I will explain how thyroid hormones affect blood pressure. When your doctor measures your blood pressure with a blood pressure monitor (sphygmomanometer), she or he inflates a cuff on your arm to collapse and then release the brachial artery under the cuff. A doctor usually uses a manual sphygmomanometer and listens to your brachial artery through a stethoscope. However there are digital blood pressure monitors available as well. When the pressure is released slowly from the cuff, the doctor listens to a first whooshing sound in your artery. This sound represents your systolic reading, it is when the blood starts flowing again in the artery, forced through by a heartbeat. Then as the cuff falls farther, the sound stops and the reading of diastolic blood pressure is taken at that moment. That reading represents the blood pressure in your artery between the heart beats, at the resting phase of the cardiac cycle. Therefore, blood pressure represents the force of blood against the arterial wall. The systolic pressure shows the power of the heart contraction and the force of blood being pumped in the artery. The second diastolic pressure represents the dilation and flexibility of the arteries.

Normal blood pressure is around 120 (systolic) and 80 (diastolic), 120/80.

High blood pressure is 140/90 or above.

The operating centre for blood pressure is present in the brain stem where signals from the body are processed. Blood pressure system is regulated by renin- angiotensin- aldosterone system and by sympathetic nerves and hormones adrenaline and noradrenaline.

While, there are many factors which can influence blood pressure, I will concentrate on thyroid dysfunction specifically in this post. Both the sympathetic and hormonal systems are deregulated in thyroid dysfunction. It has been suggested in scientific literature that there is a disconnection in the renin-angiotensin-aldosterone system in both hyperthyroidism and hypothyroidism as the functioning of kidneys is affected. Thyroid and renal function are interrelated.



People with Graves; disease have an increased rate and depth of respiration as well as higher blood pressure and a rapid heartbeat. There may be over 100 heart beats per minute. The systolic blood pressure is usually considerably higher than 120 and more raised than diastolic. Normal blood pressure is around 120 (systolic) and 80 (diastolic). In hyperthyroidism the reading for blood pressure is generally (≥140/<90 mm Hg). It is called systolic hypertension. It is also called secondary hypertension as thyroid hormones are the underlying cause of the high blood pressure. The pulse pressure is the difference between the systolic and diastolic pressure. The normal resting pulse pressure is therefore around 30-40 mmHg. People with GD have widen resting pulse pressure.

Too much thyroid hormones in blood increases metabolic rate. The heart and cardiovascular need to adjust. The excess of thyroid hormones increases the use of oxygen in the body. The sympathetic nervous system (SNS) is dominant in Graves’ disease, activated by excessive thyroid hormones. It is a system which is normally responsible for a ‘fight of flight’ body response to a dangerous and stressful situation and it releases catecholamines- epinephrine and norepinephrine from adrenal glands to accelerate the heart rate and increase blood pressure. The effects of hyperthyroidism include increased cardiac output, contractility, tachycardia, widened pulse pressure and dilation of peripheral blood vessels. Heart often goes into a ‘marathon run’. Heart related problems, such as palpitations (strong and fast beating of the heart) is a common symptom of Graves’ disease. This can also cause irregular heartbeat sometimes. Atrial fibrillation (type of a heart arrhythmia) can be seen.

Thyroid hormones increase other hormones such as aldosterone (from adrenals) and renin (from kidneys) secretion. This also increases blood volume and blood pressure by causing water to be reabsorbed along with sodium while more potassium is excreted in urine. Thyroid hormones and kidneys stimulate the development of red blood cells which also increases blood volume. Kidneys increase in mass with hyperthyroidism. Long term hypertension may lead to heart disease as it strains the heart. 


Generally, hypothyroidism can in time significantly increase diastolic pressure, raising it above 90 mm Hg. It is often called hypothyroid hypertension. This is due to the fact that over time, continuous hypothyroidism causes changes to blood vessels, they become ‘stiff’ and constricted. The systolic blood pressure reading may also become elevated. However, there is a narrow pulse pressure.

Hypothyroidism is very stressful for the body. The body has to increase blood pressure to fight the slow metabolic rate and consequences of negative effects of low thyroid levels. It tries to do it with other hormones and molecules. The sympathetic and adrenal system is activated. The levels of adrenal norepinephrine were found to be elevated in hypothyroidism. Adrenal aldosterone hormone imbalance is connected to hypothyroidism and its increased levels may result in a constriction of blood vessels and elevated diastolic (bottom number) blood pressure. Cortisol hormone levels spike at times, especially in the morning in order to raise blood pressure and to increase the heart rate. Aldosterone hormone can spike about 2am. I had found myself  awake at 2am with heart palpitation when I was on a levothyroxine hormonal replacement only. I discovered that if I had something to eat in the middle of the night, my palpitations would stop. Aldosterone hormone increases blood pressure to deliver more glucose to body tissues when levels get too low due to hypothyroidism. At the same time the kidneys function is slower and they can get smaller in size. It was found that plasma renin (produced in kidneys) and angiotensin levels were lowered with hypothyroidism. Water clearance is reduced. Hypothyroidism is a low-renin hypertensive state, which means that levels of sodium in body decrease causing fluid retention. Low thyroid hormonal levels result in the inflammation and plasticity loss of blood vessels. Arterial stiffness is an important determinant of arteriosclerosis, which increases the risk for heart attack and strokes. Thyroid hormones promote the synthesis and action of vasodilators which acts directly on muscles in our arteries. However with low levels, the vessels become less flexible. The synthesis of nitric oxide (a powerful chemical, which dilates blood vessels) from L-arginine is stimulated by T3. Imagine your heart trying to pump blood through blood vessels in the body, which cannot effectively dilate and a resulting stress and damage to the cardiovascular system.

My own experience

The levothyroxine hormonal replacement after my thyroid surgery has raised my T4 levels high over time (in the top of the T4 reference range) while my T3 hormonal levels were low borderline. I suffered from T4 thyrotoxicosis and T3 deficiency. I had developed severe high blood pressure, felt stressed, had needle and pins in my arms and suffered from severe migraines. I went to see a doctor who prescribed a beta blocker -propranolol for my blood pressure problems. I started taking the medication but after few weeks I developed severe muscle spasms, horrible pains in my jaw and terrible muscular pain coupled with some degree of depression. I went to a doctor again and I got prescribed strong antibiotics because he believed my inability to open my mouth and the pain in my jaw and ears indicated some severe throat infection. I came home, while drinking water through a straw and shaking, I had a light bulb moment and realized that propranolol stopped the conversion of T4 (levothyroxine) to T3 (active hormone) in my body. The blood pressure medication had severely depleted my T3 levels which were low to start with. I did not have throat infection or some other terrible illness, I had a severe T3 deficiency. The balance between T4 and T3 is vital. It seemed that in my case, the high T4/low T3 levels caused my high blood pressure. Both, my systolic and diastolic readings were increased but my diastolic blood pressure was significantly raised.

My experience has lead me on a journey of discovery. I had learned that balancing my hormones is important for lowering my blood pressure. I added Natural Desiccated Thyroid (NDT) to my levothyroxine treatment, which ended my blood pressure problems at the time.

Since then, I had invested in blood pressure monitor and check my blood pressure occasionally. It is important to make sure the thyroid hormonal replacement is optimal as any imbalance will eventually show in blood pressure changes. Also, levothyroxine only treatment created a state of oestrogen dominance in my body, which farther decreased T4 into T3 conversion. Natural progesterone cream also helped to get my blood pressure to completely normal levels. More on that in later posts.


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  3. Marcisz C, Kucharz EJ, Marcisz-Orzel M, Poręba R, Orzel A, Sioma-Markowska U. Changes of poststimulatory plasma renin activity in women with hyperthyroidism or hypothyroidism in relation to therapy. Neuro Endocrinol Lett. 2011; 32(3):301-7.
  4. Julia H. Hauger-Klevene, Harold Brown, Jose Zavaleta. Plasma Renin Activity in Hyper- and Hypothyroidism: Effect of Adrenergic Blocking Agents. J Clin Endocrinol Metab (1972) 34 (4): 625-629.
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Body temperature can be an indicator of thyroid function


Body temperature can be an indicator of thyroid function

Our healthy body temperature is around 36.6 degrees Celsius or 97.88 Fahrenheit. It cannot deviate from that number too much and for too long. The human molecules and enzymes inside of the cells are designed to function around this magic temperature or otherwise they get irreversibly damaged.

We need adequate and regulated energy production to maintain our health. The whole body is involved in the regulation of our body temperature. However, the thyroid hormones play a major role in the energy production and temperature regulation. Thyroid gland is the first endocrine gland to develop in a fetus at four weeks of gestation as it drives the whole development of the embryo. The growing fetus uses maternal thyroid hormones also. Every baby is tested soon after birth for thyroid hormone levels to detect possible hypothyroidism. The treatment for hypothyroidism needs to be started as soon as it is detected. The baby who was born without a thyroid gland can only live for few weeks.

Without a thyroid hormone we would eventually stop moving, our muscles (including the heart muscle) would cease to work. There are some thyroid hormones analogues produced outside of the thyroid, like in the heart or the stomach but we primary need the thyroid hormones from the thyroid to keep us alive. In someone who had their thyroid removed, taking thyroid hormones is necessary. How long a person would survive without taking thyroid hormones after thyroid removal is dependent on the individual and the stress in their life. Thyroid hormones are stored in fat cells and will get used up over time, which may take about 6 weeks or slightly longer. After that the life will cease. A partially removed thyroid does not regenerate as the cell turn over in the thyroid is very slow.

Thyroid hormone T3 starts the process of energy production in the energy houses of our cells, mitochondria. T3 needs potassium mineral to initiate the production of the energy and life giving molecule, ATP. Other nutrients, especially vitamins B are also very important.

Adrenal hormones produced by small glands above your kidneys also play an important role in regulation of body temperature and generation of energy. Impaired adrenal function may result in body temperature changes. Individuals who are chronically stressed over a period of time tend to have some degree of adrenal exhaustion and produce lower levels of cortisol which can result in temperature fluctuations and lower body temperature. High levels of cortisol due to severe stress can raise body temperature temporarily.

The conversion of T4 into T3 is dependent on the availability of thyroid hormone nuclear receptors for binding of thyroid hormones, which in turn is mediated by the levels of cortisol (also called stress hormone). Adequate levels of cortisol and T3 hormone are important for maintaining a normal body temperature. Unfortunately, hypothyroidism may cause adrenal dysfunction. Nothing works well with low thyroid.

Hypothyroidism affects the body temperature more greatly than cortisol in general. A body temperature can be an indicator of a thyroid function, however blood tests are the accurate measure of thyroid hormonal levels. Body temperature it is not considered accurate test for determining thyroid function due to the fact that other factors can play a role in changing of the body temperature, such as certain illnesses, a reduced adrenal activity (and some degree of adrenal exhaustion) and even low blood sugar. Adrenals help to stabilize the body temperature and with a poor adrenal function, body temperature might be unstable. A slight increase of temperature also occurs in the middle of cycle, at ovulation time (around day 14) in women.

Anyway, it is good to be aware of your temperature and you can take your readings to your doctor. I had a lowered body temperature when I suffered with borderline low T3 hormonal levels while on a levothyroxine only hormonal replacement after my thyroid surgery.

Woman should measure their temperature from day 5 of the menstrual period and for three consecutive days. Non menstruating women and men can do this test at any time. You can only do the reading once at the time and do not repeat.

How to measure your basal temperature:

Measure your temperature as soon as you wake up while still in bed. Try not to move too much. Stay in bed for 10 minutes and record the temperature.

Digital thermometer is best for measuring underarm temperature. Oral thermometers are also considered to be very effective; you put them deep under the tongue. Mercury thermometers should not be used due to a danger of mercury toxicity. Ear thermometers are thought to be the least accurate for this purpose.

The normal underarm temperature is between 36.6 and 36.8 degrees C. 

Anything below 36.6 degrees C (or below 97 F) might indicate hypothyroidism.

Anything above 36.8 degrees C (or 98.2 F) might indicate hyperthyroidism. 

Oral readings are slightly higher, temperature of 37.0 degrees C (98.6 F) is considered normal.