Have you ever felt like yawning right after seeing someone else yawn? You’re not imagining it - evolutionary biology can help explain why yawning is contagious. Although there is no definite consensus on why we yawn, scientists say yawning is a complicated reflex that often happens after periods of transition, such as sleeping and waking. Yawning may also help stimulate alertness and could be triggered by an increase in brain temperature.

Contagious yawning may happen because of social mirroring, where organisms can involuntarily imitate or mimic the actions of others because they think the behavior might be useful, or can lead to bonding with others on a social level. Contagious yawning may have evolved to increase vigilance within a group. For example, watching a person yawn may increase your own attentiveness to make up for the yawner’s potentially reduced attentiveness. If the yawn spreads around a whole group, with everyone witnessing a yawn, then the whole group may now be more vigilant. Do you notice any other mirroring behaviors when you’re around other people?

Are you one of those lucky people who can fall asleep easily at night? According to research, 50 to 70 million Americans have sleep-related problems - such as not being able to fall or remain asleep, excessive sleepiness during the day, or insufficient sleep. Although the amount of sleep you need depends on many factors, age groups are the most common standard to use when determining the amount of sleep you need.

The recommended amounts of sleep every 24 hours are:

If you experience regular issues with your sleep quality, timing, or duration, please contact your healthcare provider to discuss further. These issues may affect your daily activities and can be symptoms of other underlying issues, since sleep is closely related to our mental and emotional health. Are you prioritizing your sleep hygiene?

Did you know that hiccups are a symptom? Hiccups that are mild may be caused by an overindulgent meal, consuming carbonated beverages or excessive alcohol, stress, excitement, chewing gum or temperature changes. Your diaphragm is a dome-shaped muscle under your ribcage, which is an important part of the breathing process, that moves downward when you breathe in and upward when you breathe out.

When you hiccup, two things occur:

1. Your diaphragm repeatedly spasms and pulls down between breaths, which causes you you to suck in air.
2. Your glottis (part of your throat where vocal cords are) closes to prevent more air from coming in, causing you to make the “hic” noise.

Hiccups usually go away on their own, with no treatment needed or even a home remedy doing the trick. Talk to your healthcare provider if you have persistent hiccups that last over 48 hours or if your hiccups are severe and affect breathing, sleeping or eating. What remedies worked for you the last time you had the hiccups?

Have you heard the theory that stress causes hair to turn gray? It seems obvious to simplify a connection between stress and gray hair, but a number of other factors can lead to gray hair. Gray hair is often associated with older age. Generally, most gray hair is not directly related to stress, and hair does not really “turn” gray.

Cells called melanocytes add the pigment melanin to our hair during each hair cycle - the regular growth and shedding periods we all experience with our hair. Melanocytes are located in our hair follicles, which are (the pores on our bodies through which our hair grows). Once our hair follicles produce hair, the color is set - for example, if your hair starts out as brown, the follicles will never change to produce a different color such as blonde or red. Over time, your melanocytes produce less melanin, so when you grow new hair in at a later hair cycle, it is more likely to grow in as gray at that point due to the decrease in melanin. Gray hair signifies a decreased amount of melanin, while white hair completely lacks melanin. Scientists believe that smoking can cause damage to the melanocytes, leading to premature graying.

Gray hair is also influenced by our genetics, and stress can cause other hair conditions like telogen effluvium, where an affected person can shed hair up to three times faster than what is normally expected. Other illnesses that can cause gray hair are vitamin B12 deficiency, thyroid disease, and neurofibromatosis - a disorder that causes tumors and stunted development of the skin and bones. How might this information change your perception of gray hair?

Have you ever been curious about organ donation? An estimated 6,000 living donations take place every year in the US, which might also make you wonder which organs we can live without. Organs that can be donated while you’re alive include one kidney, one lobe of your liver, one lung or part of a lung, part of the pancreas, and part of the intestines. The liver is unique since cells that exist in the remaining lobe will grow until your liver is almost completely regenerated to its original size . The other organs do not regenerate, but people can still function fully without them.

Additional organs we can live without are the spleen (located on the left side of the abdomen and is involved in storing blood cells); the stomach (which may be removed due to cancer or trauma - surgeons are able to reroute the esophagus directly to the small intestine); reproductive organs in both men and women; colon or large intestine; gallbladder (located under the liver and forces bile into the intestines to help break down fats); and appendix (a thin tube connected to the large intestine that functions as part of the immune system in young children, but stops doing this in older people as other parts of the body take over to help fight infections). Are you an organ donor?