Humans have struggled with disease from the beginning of time. Whether it is due to injury, systemic failures or bugs and parasites, a person’s health can go from good to bad or it can just get weird. Apart from the common conditions like heart disease, cancer and the flu, there are some conditions that are extremely rare and have never been seen or cases are so few that research is significantly limited. Here are some disorders that you’ve probably never heard of. 

1. Uncombable Hair Syndrome

Uncombable hair syndrome (UHS) may seem like its completely made up but there are people out there who struggle with this condition. It gives people an Einstein-like appearance. Approximately 100 cases have been reported, one of whom was Taylor McGowan whose hair grew the characteristic silver-blond hair. Her hair became extremely frizzy and when her parents brought this up with medical professionals, they were told that it would fall out. Her grandmother on the other hand did some research and was the person who discovered that she had UHS.

2. Reverse-Slope Hearing Loss

In 2019, a Chinese woman named Chen experienced symptoms including nausea and ear ringing. The next morning, she woke up and could not hear her boyfriend’s voice. Further research found that she could not hear any male’s voice. It turns out that she suffered from reverse-slope hearing loss (RSHL), a condition where people could not hear low frequencies. Causes include autoimmune conditions, trauma, lack of sleep etc. but the cause of Chen’s was never identified. Luckily, she made a full recovery with rest. Some people also recover with steroid treatment or spontaneously. 

3. Riddoch Phenomenon

Milena Canning was 30 years old when her life changed forever. Not only did she contract a respiratory infection, but she survived several strokes (which left her blind) and a coma that went on for eight months. Once she woke up, she realized that she could see again, however, she could only see when things were in motion. For example, if a bird was in flight just outside the window, she could see the bird moving, but not the glass window. Canning cleverly taught herself how to see different things by moving her head in different directions. She was later diagnosed with the Riddoch phenomenon – a condition whereby patients were blind but could detect movement.

4. Semi-Identical Twins

In 2014, an Australian woman learned that she was pregnant with identical twins, who unlike fraternal twins, share a placenta. During her 14-week ultrasound, she learned that one was a boy, and the other was a girl which meant that something was wrong; identical twins could not have different genders. The twins were diagnosed as being semi-identical and this was the second recorded case in history. These twins are created when one egg is fertilized by two different sperm which means that they had three sets of chromosomes, not two, like others. They were monitored closely and were reported to be healthy shortly after their fourth birthday. 

5. Sunset Paralysis 

Pakistani brothers Shoaib and Abdul are normal children…until the sun sets. When the sun goes down, the boys become paralyzed and are unable to eat, speak or even open their eyes. The condition was never seen before the brothers and research revealed that there were two other children in the family with the disorder, who did not make it. After running a battery of tests, they discovered that the sleeping disorder was in fact, affected by sunlight, and that the likely source had to do with the fact that their parents were first cousins.