On a hot, sunny day in July 2005, Scott Knudsen, a Texas horse rancher, was standing outside his tractor barn holding his 1-year-old daughter and talking with his wife, Tracy. He remembers seeing dark clouds off in the distance, but above him was “nothing but blue skies.”

Suddenly, out of nowhere, Knudsen saw “the brightest light and heard the loudest noise you could ever imagine.” The horses were spooked, whinnying and rearing, and the chickens scattered. Knudsen recalls asking, amid the chaos and confusion, “Were we just hit by lightning?”

His wife and daughter were not struck, but Knudsen was hit by a bolt that entered his head and went out through his left hand. Miraculously, he remained standing and was able to walk back to the house. “I was grateful to be alive,” he says. But when the shock wore off, he realized he couldn't think straight. “I had bruising under my eyes, and I wasn't making sense. It was like my brain reset a little bit and then just fell off the cliff.” After his wife called their doctor, they headed to the emergency department, where Knudsen was diagnosed with a “very bad concussion” and released.

Over the next few days, his condition worsened. He developed atrial fibrillation as well as headaches and nausea, and all his dental fillings fell out. He couldn't read or write or remember the names of people he knew well. Knudsen sought advice from neurologists and speech and memory specialists and was told again that his symptoms resembled those of a concussion or other traumatic brain injury. “Every office we went to, we were told, ‘You shouldn't have lived,’ but they didn't know how to treat it,” says Knudsen, now 56.

So he focused on recovery. With the help of his wife, he began relearning how to read, write, and do math. He listened to podcasts and watched cartoons and practiced coloring within the lines alongside his daughter. It was almost a year before Knudsen could ride horses again because his balance was off. While he was sidelined, his wife would drive him down to the barn so he could spend time with his horses and other livestock, which he found comforting. He still has little memory of his life before the strike but has gotten glimpses of his past through stories and photos shared by family and friends.

Strike Statistics

Most people who are struck by lightning survive. About one in 10 people hit by lightning is killed, according to the National Lightning Safety Council, which says there were 13 lightning fatalities in the United States in 2023. The area around Tampa Bay in Florida is considered the lightning capital of the U.S., says Philip Yarnell, MD, FAAN, a Denver-based neurologist and lightning injury expert. But lightning can occur almost anywhere, depending on atmospheric conditions. A common scenario involves someone out fishing.

If lightning hits someone, it primarily injures the heart and nervous system. People who survive lightning strikes can experience a range of mild to severe symptoms, including cardiac arrest, loss of consciousness, muscle weakness or temporary paralysis, eardrum rupture, ringing in the ear, amnesia, mental confusion or slowness, and concussion-like symptoms such as headache and nausea. Few people have burn marks—which may indicate an entry or exit path of the lightning—even though a distinct fernlike pattern from the electricity passing through the skin has been popularized as a symbol of lightning strikes.

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Longer-term symptoms may include personality changes and chronic pain. Some survivors report being hypersensitive to atmospheric changes and having an uncanny sense of a storm coming. There are even rare cases of people developing unusual skills after being hit by lightning.

Scientists understand much of the physics of lightning—“it's electricity, basically made up of electrons and energy,” says Mary Ann Cooper, MD, an emergency medicine physician and professor emerita at the University of Illinois Chicago. “But we don't know the overall physiology of what happens when someone gets hit by lightning or when a ground current travels up one leg and down the other,” she says.

Experts categorize injuries based on the nature of the strike, according to the National Lightning Safety Council. Direct hits often occur in an open area, and some people think they are more likely to be fatal, but no data support that, says Dr. Cooper. A side flash is when lightning strikes a taller object and part of the current jumps from the object to a nearby victim. Side-flash victims often have taken cover under trees to escape the rain.

A ground strike occurs when lightning hits the ground or an object near a person and the electrical energy travels through the ground. This can cause group casualties of people or animals. Lightning also can strike a person through conduction, with the current traveling along a fence or through a home's water pipes or phone lines, which is why parents may warn children to stay away from sinks or bathtubs during a storm. Another potentially deadly type of lightning is called a “streamer.”

Parsing the Literature

Dr. Cooper became interested in lightning while in medical school in the 1970s. Growing up in the Midwest, she'd watched her father revel in lightning and big thunderstorms “like it was the Fourth of July.” When she delved into the medical literature, however, she was surprised to see very little on what lightning could do to the body. An internal medicine textbook had only one sentence about it, she says.

She began to compile a systematic characterization from scattered reports. In a still-cited article that Dr. Cooper published in Annals of Emergency Medicine in 1980, she reviewed 66 patient cases (including eight of her own) and found that 72 percent had lost consciousness, 30 percent had cardiopulmonary arrest, and 70 percent received cardiopulmonary resuscitation (CPR). Of those with neurologic symptoms, 69 percent had some paralysis, and 86 percent had confusion or amnesia.

Survivors sometimes describe their brain deficits as little black holes, says Dr. Cooper. “We never know the extent of the damaged areas or how they might affect certain functions.” Others report experiencing a continuous state of heightened alertness after getting struck.

Increased public awareness about the dangers of lightning has helped reduce the average number of fatalities annually in the U.S. from about 73 in the 1980s to around 20 in the past decade. But lightning deaths and injuries remain a bigger problem globally, says Dr. Cooper, who is director and president of ACLENet (African Centres for Lightning and Electromagnetics Network), which provides programming worldwide on lightning safety.

The case of a cyclist who became a paraplegic after he was hit by lightning piqued the interest of Dr. Yarnell, a consulting neurologist at St. Anthony Hospital in Lakewood, CO, who went on to co-found St. Anthony's Lightning Data Center, which serves as a repository for medical and scientific research and a large collection of survivors' stories. Since reading the case of the bicyclist who was hit while taking cover under a tree during a storm, Dr. Yarnell has learned a lot about the effects of lightning strikes—including that the electric current can send a person into cardiac and respiratory arrest. If a person is unconscious and there is no danger of another strike, emergency personnel should perform CPR. (There is no risk of becoming electrocuted by touching someone who has been struck by lightning, says Dr. Yarnell.)

Immediate concerns such as heart arrhythmia and eardrum rupture can be addressed by emergency personnel, but lingering effects may not be evident right away. Some people exhibit symptoms similar to those from a concussion or other brain injury, but usually no telltale signs can be seen on an MRI unless the lightning strike caused a stroke or bleed. Functional magnetic resonance imaging, a more sophisticated type of MRI done on the brain, may reveal damage in the brain's circuitry in people who've been struck, but the test is still investigational, says Dr. Yarnell. “The hypothesis is that a lightning strike is a shock to the nervous system,” he says. People may recover from short-term injuries, but some may have neuropsychological or neurocognitive symptoms days or weeks later.

Unusual Consequences

In rare cases, people struck by lightning develop an interest in music or art. Tony Cicoria, 72, a semiretired orthopedic surgeon who lives in York, ME, became obsessed with learning to play the piano and composing music after he was struck by lightning in 1994. “I started to have this craving to hear and play classical music,” says Cicoria, who had been a rock fan and had taken piano lessons only briefly when he was 7.

Cicoria had been hit by lightning while using a pay phone outside a pavilion in a park near Albany, NY. “Suddenly there was this large flash of light, and a loud crack occurred almost simultaneously,” he recalls. “I saw this huge blaze of light come out of the phone, and it hit me in the face.”

He had an out-of-body experience in which he saw himself lying on the ground, with people standing over him. “I could see and hear everybody, but no one could hear or see me,” Cicoria says. It was like a dream, he says, “and then I felt like I had fallen into a river of pure positive energy. There was nothing but love and peace in it.” The high and low moments of his life flashed before him.

Cicoria was resuscitated with CPR by a woman waiting to use the phone who happened to be a nurse, and police and an ambulance were summoned. Cicoria declined to go to the emergency department, believing he had survived unscathed. Later, on the advice of his family doctor, he saw a cardiologist and a neurologist. The only symptom he had was some mental fuzziness, which cleared in a week, although he didn't feel quite back to normal.

He returned to work but began thinking about and listening to classical music. As luck would have it, his children's babysitter needed her piano stored for a year, so he took it in and started to teach himself to play. Then one night he had an odd dream about being on stage in a tux playing an elaborate piece of music he was not familiar with in his waking hours. “From that moment, whenever I went near the piano or sat next to the piano, the music from the dream played in my head,” he says.

Cicoria took piano lessons and attended music camps, practicing early in the morning and late at night, and progressing at an uncanny pace. He also composed music, including the mysterious piece in his dream, which he dubbed “The Lightning Sonata.” Cicoria's experience was described in famed neurologist Oliver Sacks' 2007 book Musicophilia: Tales of Music and the Brain. “Oliver felt strongly that the lightning, the electricity, had somehow allowed me to access a part of my brain I did not know I had access to, or caused the growth of neurons that make connections involved in musical ability,” Cicoria says.

As for Scott Knudsen, he now does public speaking around the country about his lightning experience, hoping to educate people about these risks and motivate them to try to stay positive even in tough situations. At a recent event with veterans, he felt a special connection because some of them also may have sustained brain injuries.

Knudsen, who still owns a horse ranch in Texas—appropriately named Lightning K Ranch—also hosts a podcast,  Cowboy Entrepreneur. He has written two books, and he and his wife created the Cowboy Entrepreneur Foundation.

“Tracy and I took the lightning strike and made it positive,” Knudsen says. “We don't want to waste a moment of life.”

Resources Related to Lightning

• Lightning Safety Council
• Lightning Strike and Electrical Shock Survivors International
• National Weather Service