Maybe you feel worn out. Perhaps you’re also having trouble losing weight. Generally, you just don’t feel 100%.

Could it be Hashimoto’s disease? This common autoimmune thyroid disorder is when your immune system (which fights off viruses and bacteria), mistakenly attacks a part of your body. In this case, it’s your thyroid – a gland located at the base of your neck – and can cause low thyroid hormones levels (hypothyroidism).

Hypothyroidism affects one in 33 Australians and Hashimoto’s is one of the most common thyroid conditions in first-world countries.

While symptoms can be subtle, untreated Hashimoto’s can cause long-term problems with your heart, memory and fertility. Here is what you need to know.

What happens when you have Hashimoto’s?

Your thyroid gland is a butterfly-shaped gland in the neck. It is essential in regulating things like muscle function, digestion, metabolism, the heart and lungs. In children, thyroid hormones are also needed for normal growth and development.

Hashimoto’s thyroid disease, named after the Japanese doctor who discovered it in 1912, is also known as Hashimoto’s thyroiditis or chronic lymphocytic thyroiditis. The disease can cause the immune system to mistakenly produce proteins called antibodies (thyroid peroxidase and thyroglobulin). These can cause inflammation and long-term damage to the thyroid gland. Over time, as thyroid tissue is inflamed and/or destroyed, there can be a decrease in the production of thyroid hormones (hypothyroidism).

Hashimoto’s can present subtly at first. If you only have antibodies with no change in thyroid levels, it is likely you won’t have any symptoms.

However, as the disease progresses, you may experience fatigue, weight gain (or difficulty losing weight), increased sensitivity to the cold, constipation, dry skin, muscle aches, irregular or heavy menstrual cycles, enlarged thyroid (goitre) and occasionally hair loss, including at the ends of your eyebrows.

What causes Hashimoto’s thyroid disease?

Several risk factors can contribute to the development of Hashimoto’s including:

• genetic risk – your risk is higher if you have family members with Hashimoto’s

• gender – women are up to ten times more likely than men to develop the disease

• age – you are more likely to develop the disease from 30 to 50 years of age

• autoimmune condition – having another autoimmune condition like systemic lupus, Type 1 diabetes and celiac disease increases your risk

• excessive iodine intake and radiation exposure may also increase risk in people who are already genetically at greater risk.

What are the long-term risks?

Long-term, untreated Hashimoto’s thyroiditis can cause heart issues, higher cholesterol levels, nerve damage (peripheral neuropathy), reduced cognition and infertility.

In pregnancy, Hashimoto’s has a higher risk of pre-eclampsia (high blood pressure affecting several organs), premature birth, placental abruption (when the placenta separates from the inner wall of the uterus before birth) and, in severe cases, pregnancy loss.

The disease has also been linked with an increased risk (but low incidence) of the lymphocytes of the thyroid turning into cancer cells to cause thyroid lymphoma.

How is Hashimoto’s diagnosed?

Diagnosis can be confirmed with a blood test to check thyroid levels and antibodies.

Thyroid peroxidase antibodies are commonly present but about 5% of patients test antibody-negative. In those people, diagnosis depends on the thyroid levels, clinical presentation and ultrasound appearance of general inflammation. An ultrasound may not be required though, especially if the diagnosis is obvious.

Three hormone levels are tested to determine if you have Hashimoto’s.

Thyroid stimulating hormone (TSH) is produced by the brain to speak to the thyroid, telling it to produce two types of thyroid hormones – T3 and T4.

If you have either relative or absolute thyroid hormone deficiency, a test will show the stimulating hormones as high because the brain is trying to get the thyroid to work harder.

Can it be treated?

The management of Hashimoto’s depends on the severity of the thyroid levels. Up to 20% of the population can have antibodies but normal thyroid levels. This is still Hashimoto’s thyroid disease, but it is very mild and does not require treatment. There is no current treatment to reduce antibody levels alone.

Because thyroid peroxidase antibodies increase the risk of abnormal thyroid levels in the future, regular thyroid testing is recommended.

When the thyroid stimulating hormone is high with normal thyroid hormone levels it is termed “subclinical hypothyroidism”. When it is paired with low hormone levels it is called “overt hypothyroidism”. The first is a mild form of the disease and treatment depends on the degree of stimulating hormone elevation.

Overt hypothyroidism warrants treatment. The main form of this is thyroid hormone replacement therapy (levothyroxine) with the dose of the drug adjusted until thyroid levels are within the normal range. This is usually a lifelong treatment but, once the dose is optimised, hormone levels usually remain relatively stable.

In some people with very enlarged thyroid glands causing compressive symptoms (such as difficulty swallowing or breathing), thyroidectomy (surgical removal of the thyroid) is considered.

Hashimoto’s thyroiditis is a common condition caused by your body’s immune system incorrectly damaging to your thyroid and can go undetected. Long-term, untreated, it can cause issues with your heart, cognition, and fertility. It can be diagnosed with a simple blood test. Speak to your doctor if you have any concerns as early diagnosis and treatment can help prevent complications.

Aakansha Zala, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

People who are taller are at greater risk of developing cancer. The World Cancer Research Fund reports there is strong evidence taller people have a higher chance of of developing cancer of the:

• pancreas
• large bowel
• uterus (endometrium)
• ovary
• prostate
• kidney
• skin (melanoma) and
• breast (pre- and post-menopausal).

But why? Here’s what we know, don’t know and suspect.

A well established pattern

The UK Million Women Study found that for 15 of the 17 cancers they investigated, the taller you are the more likely you are to have them.

It found that overall, each ten-centimetre increase in height increased the risk of developing a cancer by about 16%. A similar increase has been found in men.

Let’s put that in perspective. If about 45 in every 10,000 women of average height (about 165 centimetres) develop cancer each year, then about 52 in each 10,000 women who are 175 centimetres tall would get cancer. That’s only an extra seven cancers.

So, it’s actually a pretty small increase in risk.

Another study found 22 of 23 cancers occurred more commonly in taller than in shorter people.

Why?

The relationship between height and cancer risk occurs across ethnicities and income levels, as well as in studies that have looked at genes that predict height.

These results suggest there is a biological reason for the link between cancer and height.

While it is not completely clear why, there are a couple of strong theories.

The first is linked to the fact a taller person will have more cells. For example, a tall person probably has a longer large bowel with more cells and thus more entries in the large bowel cancer lottery than a shorter person.

Scientists think cancer develops through an accumulation of damage to genes that can occur in a cell when it divides to create new cells.

The more times a cell divides, the more likely it is that genetic damage will occur and be passed onto the new cells.

The more damage that accumulates, the more likely it is that a cancer will develop.

A person with more cells in their body will have more cell divisions and thus potentially more chance that a cancer will develop in one of them.

Some research supports the idea having more cells is the reason tall people develop cancer more and may explain to some extent why men are more likely to get cancer than women (because they are, on average, taller than women).

However, it’s not clear height is related to the size of all organs (for example, do taller women have bigger breasts or bigger ovaries?).

One study tried to assess this. It found that while organ mass explained the height-cancer relationship in eight of 15 cancers assessed, there were seven others where organ mass did not explain the relationship with height.

It is worth noting this study was quite limited by the amount of data they had on organ mass.

Another theory is that there is a common factor that makes people taller as well as increasing their cancer risk.

One possibility is a hormone called insulin-like growth factor 1 (IGF-1). This hormone helps children grow and then continues to have an important role in driving cell growth and cell division in adults.

This is an important function. Our bodies need to produce new cells when old ones are damaged or get old. Think of all the skin cells that come off when you use a good body scrub. Those cells need to be replaced so our skin doesn’t wear out.

However, we can get too much of a good thing. Some studies have found people who have higher IGF-1 levels than average have a higher risk of developing breast or prostate cancer.

But again, this has not been a consistent finding for all cancer types.

It is likely that both explanations (more cells and more IGF-1) play a role.

But more research is needed to really understand why taller people get cancer and whether this information could be used to prevent or even treat cancers.

I’m tall. What should I do?

If you are more LeBron James than Lionel Messi when it comes to height, what can you do?

Firstly, remember height only increases cancer risk by a very small amount.

Secondly, there are many things all of us can do to reduce our cancer risk, and those things have a much, much greater effect on cancer risk than height.

We can take a look at our lifestyle. Try to:

• eat a healthy diet
• exercise regularly
• maintain a healthy weight
• be careful in the sun
• limit alcohol consumption.

And, most importantly, don’t smoke!

If we all did these things we could vastly reduce the amount of cancer.

You can also take part in cancer screening programs that help pick up cancers of the breast, cervix and bowel early so they can be treated successfully.

Finally, take heart! Research also tells us that being taller might just reduce your chance of having a heart attack or stroke.

Susan Jordan, Associate Professor of Epidemiology, The University of Queensland and Karen Tuesley, Postdoctoral Research Fellow, School of Public Health, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.