As we grow up, we are programmed to believe things taught to us. So, we end up believing and practicing things which are actually completely wrong. The same goes for the field of medicine. Since early times, people didn’t have a vast understanding of medicine. Hence, it gave rise to several myths which were passed down through generations. Thankfully nowadays people are becoming aware of their body and starting to question before following any medical recommendations blindly. This quest for knowledge has brought forward many medical myths. Here are 10 such medical beliefs that are actually myths.

Myth #1

People should drink at least eight glasses of water a day.

Reality: The amount of water an individual needs to consume depends on many factors including the person’s health, activities, and the place of residence.

The idea that to maintain good health a person should drink at least eight glasses of water a day is believed to have originated from a recommendation by the Food and Nutrition Board in 1945. Most people don’t know that there was another sentence following this recommendation. The sentence read, “Most of this quantity is contained in prepared foods.” The second part has been generally ignored and thus started the myth of drinking eight glasses of water per day.

According to the Mayo Clinic, people need to drink only the amount of water which is necessary to replace the water lost throughout the day. The amount of water lost by our body depends on various factors related to our body and daily life. For example, a person doing physical work loses more water than a person who sits behind a desk all day. Also, a person living in hot or humid weather loses more water than a person living in cold weather.

Apart from drinking water, our body gets water through various other sources such as the fruits and vegetables we eat. Juice, milk, and even caffeinated drinks provide our body enough fluids. And whenever our body is in need of water, our brain lets us know by making us feel thirsty. In fact, there are many existing studies which show that consuming excessive water can actually be harmful to our body. Excess water can drop the level of sodium in the blood causing water intoxication (also known as hyponatremia).(1,2,3,4)

Myth #2

Mobile phones create considerable electromagnetic interference in hospitals.

Reality: Mobile phones interfere with very few medical devices and only if the mobile phone is less than one meter from the device.

While entering a hospital premise we are often greeted with the sign: “Switch off your mobile.” It is a common belief that cell phones cause electromagnetic interference which can affect the operation of various medical equipment used for monitoring patients. Surprisingly, there is no concrete evidence to back up this belief.

In a survey done in 2004, it was found that more than 60% of the doctors leave their phones switched on in operation theaters and other such high-risk areas. Some studies in the United Kingdom show that mobile phones cause only 1 to 4% interference, and only when the phone was within a meter of the medical equipment. In 2005, 510 tests were performed at the Mayo Clinic. These tests studied the interference of six mobile phones on 16 medical devices. It was found that the incidence of clinically important interference was only 1.2 %.

As modern phones are improving, they are causing even less interference. Also, modern medical equipment is better shielded. So, unless you keep your phones right next to critical care equipment, the chances of interference and equipment malfunctioning is quite low.(1,2,3)

Myth #3

Schizophrenia causes a person to have split personalities.

Reality: Schizophrenia and multiple personality disorder are two different mental disorders.

National Institute of Mental Health defines schizophrenia as “a chronic and severe mental disorder that affects how a person thinks, feels, and behaves. People with schizophrenia may seem like they have lost touch with reality.” People suffering from schizophrenia often suffer from delusion and hallucination. They may have false beliefs or may hear or see things that do not exist. Many people interpret these aspects of schizophrenia as having a split personality.

Actually, split personality, also known as dissociative identity disorder (DID), is an entirely different illness. A person suffering from DID develops multiple identities. Each identity has its own voice, manner, and characteristics. DID usually occurs in people who have experienced severe trauma during their childhood.(1,2,3,4)

Myth #4

We use only 10% of our brains.

Reality: We use virtually every part of our brain, and most of the brain is active almost all the time.

One of the most popular beliefs about the brain is that we use only 10% of our brain. The origin of this fact can be traced back to 1800s. But this is a completely wrong information. The 10% use of the brain myth is actually an urban legend.

According to neurologist Barry Gordon, we use all parts of our brain. His statement had been backed by numerous pieces of evidence. Brain scans show that our brain is always active. A slight damage in any part of our brain can produce drastic changes. This would not have been possible if we used only 10% of our brain. Using brain imaging, doctors have found that even while we are asleep all parts of our brain show some level of activity.(1,2,3,4)

Myth #5

Cracking knuckles cause arthritis.

Reality: There is no link between cracking knuckles and arthritis.

In 2009, a Californian doctor, Dr. Donald Unger, received an Ig Noble Prize for an experiment which proves there is no link between knuckle cracking and arthritis. For 50 years he cracked the knuckles of his left hand only, twice a day. But he never cracked the knuckles of his right hand. At the end of the experiment, Unger found that none of his hands developed arthritis.

Unger is not the first person to do research on this topic. Many studies have been conducted before, and all of them had the same conclusion. But knuckle cracking isn’t an absolutely safe activity to perform. Even though it doesn’t cause arthritis, it can cause inflammation, soft tissue damage, and weakened hand grip.(1,2,3,4)

Myth #6

Vaccines cause autism.

Reality: Vaccines do not cause autism or autism spectrum disorders.

In 1998, British researchers published a paper which stated that MMR vaccine (measles-mumps-rubella vaccine) causes autism. Their study received huge publicity as lots of kids were being diagnosed with the condition. As the study became popular, other doctors too started their own research to find the link between vaccines and autism. But none of them found any evidence supporting the claim. Later, it was discovered that the researcher who published the study was bribed. So, the journal that published the claim eventually retracted it.

A year after the British study, a new fear regarding vaccines started developing. It was thought that a substance called thimerosal used in children’s vaccine can cause autism. Again, numerous studies were conducted, but researchers didn’t find any link between the two. Still, in 2001 at the urging of American Academy of Pediatrics and the U.S. Public Health Service, thimerosal was taken out of most children’s vaccines.(1,2,3)

Myth #7

Reading in dim light ruins your eyesight.

Reality: Dim lighting does not cause any adverse effect on our eyesight, rather it tires out our eyes more quickly.

During our childhood, most of us have snuck in comic books to read them under the covers at night. Whenever we got caught, we used to get a good lecture on how dim light can ruin our eyesight, and also how we would be late for school the next morning. While the late for school part usually turned out to be true, but the ruined eyesight part is actually false.

Reading in dim light does not cause any long-term harm to our eyes. Usually, dim lights make it difficult for the eyes to focus. This puts a strain on eyes, and that’s why it can cause short-term eye fatigue. But it does not damage the structure or function of the eyes.(1,2,3)

Myth #8

Rust causes tetanus infection.

Reality: Rust does not cause the tetanus virus. It is caused by the Clostridium tetani bacterium that is generally found in dirty environments.

The idea that rust causes tetanus originated during World War II when many soldiers got infected and even died due to this disease. Most of these soldiers got infected due to deep puncture wounds rather than a small cut from rusty nail or metal. But the myth persisted, and people began receiving a tetanus shot even after a scratch or prick from any rusty metal or nail.

Tetanus is actually caused by a bacteria called Clostridia tetani. This bacteria thrives in dirty environments. Metals rust when they are not in use, and dirt begins gathering around them. This dirt may harbor the bacteria Clostridia tetani which can enter our body through an injury causing tetanus.

Basically, a person gets infected from tetanus due to the bacteria growing in dirt and not due to the rust. So, even if you get injured from a non-rusted, non-metal, but dirty object, then you are at a risk of contracting tetanus.(1,2,3)

Myth #9

Eating turkey makes people drowsy.

Reality: Turkey does not make people sleepy. People feel sleepy after a Thanksgiving meal because they tend to overeat.

Thanksgiving dinner is usually considered incomplete if we don’t stuff ourselves with turkey.  And as soon as the dinner ends, we start feeling sleepy. The sleep following the Thanksgiving dinner is normally blamed on the turkey. It is a common belief that turkey tends to make us feel sleepy as it contains the amino acid L-tryptophan. But that’s not the truth.

Turkey contains less L-tryptophan than chicken. But no one feels sleepy after consuming chicken or other poultry. The amount of L-tryptophan in turkey is almost comparable to other poultry. The sleep after Thanksgiving dinner is actually induced from over-eating. There are some other reasons too such as alcohol consumption and high amounts of fat and carbohydrate in the Thanksgiving meal that causes drowsiness.(1,2)

Myth #10

Men can’t get breast cancer.

Reality: Men can get breast cancer but it’s very rare.

It is a common belief that breast cancer can only occur in women. But both men and women can get breast cancer, even though it is quite rare in men. This is because like women, men too have breast tissue, although in a much smaller amount.

In the UK, compared to about 55,000 women, around 390 men are diagnosed with breast cancer each year. Overall, it is estimated that less than 1% of all breast cancer develops in males. Usually, men diagnosed with breast cancer are over 60. But it can affect younger men too. Men who have certain testicular conditions like orchiectomy, a family history of breast cancer, gynecomastia, or severe liver disease are at an increased risk of developing breast cancer.(1,2)