Harmful Effects of the Sun on Humans

While sun exposure is not entirely bad and is necessary for creating vitamin D to boost the immune system, too much sun exposure can be harmful. After a cold winter, many begin their tanning pursuits, hoping to become golden brown by summer’s end. 

Unfortunately, too much sun can harm your health in multiple ways. We want your family to stay safe this summer and all year. 

While we think about sun exposure dangers more in the summer, you can experience harmful consequences any time of the year, even in winter. Practicing caution and being aware of the risks of sun exposure on humans will protect your family. 

Why Can Sun Exposure Be Harmful?

Most everyone enjoys the sun, whether young or old. Unfortunately, the sun gives off rays that can harm humans. The sun emits three types of ultraviolet (UV) rays: UVA, UVB, and UVC. Both UVA and UVB rays are most common, but UVC rays are the deadliest.

Although you cannot see the sun’s UV rays, they can pierce through your skin’s outer layers and into the dermis. If your dermis is exposed to too much sun, sunburn and eventual harm result. 

Top Harmful Effects of UV Rays on Humans

Most people have experienced at least a minor sunburn, but some have suffered from dangerous effects. The following offers insight into some of the effects you should be aware of before heading out for a day in the sun. 

Skin Damage (Short-Term)

Most people do not realize it is possible to get a sunburn in only 15 minutes, depending on the time of day. Typically, sunburns will not show for up to six hours, which is why many people do not realize how fast they occur. 

In addition to skin reddening and pain, people also experience blistering. Severe sunburns can lead to second-degree burns. 

Although the damage from sunburns is short-lived and resolves on its own, further damage can occur with ongoing exposure. The more sunburns a person experiences as a child, the greater the risk of them developing skin cancer later in life. 

Skin Damage (Long-Term)

The long-term effects of repeated sun exposure can lead to premature aging and more wrinkles. Even if you do not get sunburned often, exposing your skin to UV rays can lead to wrinkles, age spots, and thinner skin from dead cells. 

People who spend too much time in the sun often bruise easily. Prolonged exposure to the sun’s UV rays can damage the skin’s structural components by altering the DNA, which results in skin cancers. 

UV exposure also causes the melanin in the skin to clump together, leading to moles and freckles. These moles and freckles can eventually become cancerous, especially among those with light skin. 

Prolonged exposure to UV rays can lead to different types of cancer. 

Basal-Cell Carcinoma (Skin Cancer)

This type of cancer is the most common form and also the least serious, though it should never be ignored. Basal-cell carcinomas often appear as a scabby, flaky area that does not heal. 

Although this type of cancer usually does not spread, it can deepen and become more challenging to treat. Doctors typically use ablation to remove these skin lesions. 

Squamous-Cell Carcinoma

Squamous-cell carcinomas are the most serious form of skin cancer. Although this skin cancer occurs because of sun exposure, it can also arise on burn scars and ulcerations.

These skin cancer lesions frequently need to be removed via surgery. Sometimes the cancer can spread to the lymph nodes and eventually other organs. 


Melanoma is the most serious of skin cancer types and can become deadly. Melanoma can spread to the lymph nodes and other organs, including the brain, liver, and lungs. 

Those with moles on the outer layer of their skin must monitor their skin carefully and watch for skin changes. Young adults with a family history of melanoma should schedule regular check-ups with their doctors. Once a person develops melanoma, they are more likely to experience it again in the future. 

While sunburns at any time can lead to the risks of skin cancer development, those occurring in early childhood are most damaging. 

According to the Skin Cancer Foundation, children who experience five or more sunburns from too much sun exposure increase their lifetime risk of developing melanoma by 80%. 

Heat Stroke

Heat strokes are serious medical emergencies. A heat stroke begins with muscle cramps and progresses quickly. Eventually, a person can suffer brain damage if they do not cool down or receive treatment. 

Many people mistakenly believe heat strokes only happen to older people. Even children can fall victim to heat strokes after prolonged sun exposure. 

When dehydration is combined with extreme heat, the results can be deadly. Heat strokes occur when the body’s core temperature rises above 105 degrees Fahrenheit. The following are some of the symptoms associated with heat strokes.

  • Lightheadedness and dizziness
  • Severe headache
  • Muscle cramps and weakness that become pronounced
  • Mental confusion
  • Staggering 
  • Shallow breathing
  • Rapid heartbeat
  • Nausea and vomiting

A heat stroke can eventually lead to loss of consciousness or a coma. If someone exhibits the above symptoms, they need immediate medical attention. Get the person to shade and remove any unnecessary clothing. 


Health experts warn many people suffer from chronic dehydration. While mild dehydration is usually not damaging to the body, mild dehydration becomes severe when coupled with extreme heat. Severe dehydration can lead to death. 

One of the hallmark signs of dehydration is dark, yellow urine. You may also experience the following symptoms if you become dehydrated.

  • Increased thirst
  • Increased sweating
  • Decreased urine output
  • Swollen tongue and dry mouth
  • Heart palpitations that worsen
  • Confusion and sluggishness
  • Loss of consciousness

When spending time in the sun’s rays, hydration is essential. Encourage everyone to drink plenty of water or enjoy a popsicle to cool off. 

Solar Urticaria (Hives)

While rare, some people appear to be allergic to the sun because they break out in hives within five minutes of sun exposure. Usually, the hives and other symptoms go away within two hours after exposure. 

This rare condition may also lead to headaches, nausea, and muscle weakness. Females are more likely to suffer from solar urticaria than males, and this condition can become disabling. 

Eye Injuries and Damage

Many people do not realize the harmful consequences the sun can have on their eyes. If you venture into the sunlight without sunglasses, you could be putting your eye health in danger. 

If you experience long-term exposure to UV rays, even in small amounts, you are at a greater risk of developing macular degeneration and cataracts. 

Your eyes can also become sunburned, just like your skin cells. The technical name for eye sunburns is photokeratitis. Not only does this condition cause discomfort, but it can also lead to temporary damage to your cornea. 

The symptoms of photokeratitis include the following: 

  • Redness 
  • Pain and tenderness
  • Blurred vision
  • Excessive tearing
  • Swelling
  • Sensitivity to light
  • Twitching in the eyelids
  • A gritty sensation or feeling like something is in your eye
  • Seeing halos around objects
  • Headaches
  • Temporary vision or color loss 

The symptoms of photokeratitis typically do not last over 24 hours. The longer your eyes are exposed to UV light, the more serious the symptoms become. 

Tips for Protecting Your Skin Cells From the Sun

Sun protection is essential for all parts of your body. Too much UV exposure is damaging and can cause the above issues. The following tips will help you protect yourself and those you love while in the sun. 

  • Always wear and reapply sunscreen, even if you will only experience mild exposure to the sun. Choose a sunscreen lotion that is at least 30 SPF. 
  • Wear sunglasses that offer full ultraviolet radiation protection, blocking 100% of rays. Choose a wraparound style for the best results. 
  • Avoid being out in the sun during peak hours. 
  • Wear long sleeves and pants to cover as much flesh as possible. 
  • Wear a wide-brimmed hat to protect your face, scalp, and neck from sunburns. 
  • Stay hydrated. If you know you will be in the sun for long periods, take breaks and drink plenty of water. 

Too Much Sun Can Be Unhealthy

Although a little sun exposure benefits the body, helping it make vitamin D, overexposure to UV rays can be harmful. By taking the precautions above, you can avoid the dangers of the sun, including sunburns, eye damage, and skin cancer.