We have all seen movies where right before the hero starts fighting, he cracks his knuckles and makes it look like the coolest thing in the world! But then our parents told us that you should not crack your knuckles because that weakens your grip and hand strength. But is that true? While many people do say that they experience a small loss in strength immediately after they crack their knuckles, but are their long-term effects to it? And what is the sound actually coming from?

The reason why people crack their fingers is because the evident and sharp crack noise causes a sense of relief. Many people also do it when they have done an activity that required them to work with their hands a lot like typing or sewing, giving themselves a sense of satisfaction, similar to stretching after doing hard work. That "crack" sound can make some people cringe, while others find it strangely satisfying. Cracking your knuckles is a pretty common habit, but there are a lot of misunderstandings about it. Some people do it without even thinking, others can't stand the noise, and some can't crack their knuckles at all. You might have been told as a kid that it causes arthritis or makes your fingers swell up. But those are just old wives' tales. There's a real science behind this habit, and it's more interesting than you may think.

Why Do Knuckles Make That Popping Sound?

The "crack" isn't actually bones breaking or anything bad happening to your joints. It's a normal thing called "crepitus." This just means harmless popping, snapping, or grinding sounds that come from your joints. The main reason you hear this sound is because of gas bubbles in the fluid that cushions your joints. This fluid is called synovial fluid. When you move or stretch, these tiny bubbles form and then pop, making the sound. It's totally normal and doesn't hurt you. Sometimes, especially in bigger joints like your knees, shoulders, or ankles, the sound can also happen when the stretchy tissues that connect your bones (ligaments and tendons) move slightly and then snap back into place.

After you crack your knuckles, you can't usually do it again right away. You have to wait a bit. That's because the gas bubbles in your joint fluid have already popped, and it takes a little while for them to build up again. While cracking your knuckles doesn't give you arthritis, doing it too much might cause some problems. Doctors say that cracking them too often could make your joints a little wobbly and might even make your grip weaker. Also, if the stretchy tissues in your joints keep snapping over your bones, they can get irritated and sore.

When Joint Popping Might Mean Something More

Sometimes, a pop in your joint is just like cracking your knuckles, nothing to worry about. But other times, it can be a sign of something else. As we get older, the cushiony stuff in our joints, called cartilage, can start to wear down. This cartilage helps your bones move smoothly. When it gets thin or uneven, the bones can rub together, and that can make a grinding or popping sound. This is different from the pop you get from gas bubbles. If this grinding sound happens along with pain, it could be a sign of osteoarthritis. This is a type of joint problem that's more common in older people, but younger people can get it too, especially after a joint injury. If your joints hurt, especially in the morning or after you've been sitting still for a while, feel wobbly, or are hard to move, it's a good idea to see a doctor.

Heart attacks were largely seen as a disease of older age. But lately cardiologists have been increasingly treating patients in their 20s and 30s, including people who appeared healthy, exercised regularly and had no obvious warning signs.

One of the youngest patients treated by Dr Zakia Khan, Director – Interventional Cardiology, Fortis Hospital, Mumbai, was just 18 years old. Dr. Khan told HealthandMe that the young man was a heavy smoker and developed chest pain, which he initially ignored.

“At such a young age, people often do not think of chest pain as a possible heart problem, which can delay treatment,” Dr Khan said.

Dr Girish B Navasundi, Cardiologist, Apollo Hospitals, Bangalore, also told HealthandMe that he has treated an 18-year-old college student with a 100% blockage in one of his coronary arteries. Dr. Navasundi revealed that the patient smoked and used recreational drugs.

These cases highlight a grim reality that being young does not make a person immune to heart disease. On World Heart Day, we spoke to cardiologists about their young heart attack patients, the biggest red flags they saw, and what their advice for young people about maintaining a healthy heart.

Heart Attacks Are On The Rise Among Young People

Smoking remains an important reason, but doctors say it is rarely the only factor. Dr Khan says she commonly sees a combination of various factors. Experts also say that a person can look healthy on the outside while carrying several cardiovascular risk factors underneath.

She said, “Smoking is one of the common risk factors I have seen in younger patients. Along with this, family history of premature coronary artery disease and an unhealthy diet, particularly one high in junk food and trans fats, can significantly increase risk. Some patients may otherwise appear healthy.”

Dr Navasundi says many young patients appear well and may even report having no symptoms. But several lifestyle factors can contribute to risk.

“Most of them have four lifestyle factors in the form of stress at work, smoking, improper sleep, lack of physical exercise as some of the precipitating factors for heart attack. Also at least one third of them have had abnormally high cholesterol, blood sugar or blood pressure,” he said.

Also read: Inflammation May Be Quietly Changing Your Heart: Study Finds 43% Higher Risk Of Heart Attack & Stroke

Symptoms May Not Look Like A Heart Attack

According to the doctors, one of the biggest problems among younger people is that they don't recognise their symptoms as a cardiac problem. Chest pain is a common symptom, but young patients may dismiss it as acidity, gas, indigestion or even muscle pain.

“Many young people describe it as acidity, gas or indigestion and do not take it seriously. Some ignore the discomfort altogether, assuming it will settle on its own. This can delay medical attention,” Dr Khan said.

Dr Navasundi has seen an even wider range of symptoms. “Common symptoms that they’ve had is uneasiness in the chest, centre of the chest, in the form of burning or choking or as pain, gas, not able to burp or tightness in the chest. Some of the people have had slightly unusual symptoms such as pain only in the left arm or both arms or upper back without having pain in the front of the chest.”

Other patients, he said, have reported excessive tiredness, jaw pain, a sensation of something being stuck in the throat, or a feeling of gas and not being able to burp.

The problem is compounded by the misguided belief that heart attacks happen to older people. Young adults may therefore wait for symptoms to become severe before seeking help, which may lead to preventable fatalities.

Also read: Your Heart After A Cardiac Event: What Recovery Really Looks Like

Sometimes It Could Be Genetic

The experts also say that not every young heart-attack patient may arrive with an obvious lifestyle explanation. Dr Navasundi says some patients have clotting disorders, familial hypercholesterolaemia or a strong family history of premature heart disease.

“Some young people truly have unconventional risk factors like clotting disorders, familial hypercholesterolaemia, that means very high cholesterol from a very young age, and a strong family history of premature heart disease even when these people have a very disciplined lifestyle including eating very healthy, exercising very well, sleeping well. In spite of that, their genetic make-up, the gene and family history make them more vulnerable.”

Dr Khan similarly emphasises that family history can be a warning sign even when someone feels completely healthy.

“A person may feel completely healthy but still carry an inherited tendency towards cardiovascular risk. Knowing your family history can help you identify the need for earlier screening and lifestyle changes.”

Also read: How To Reduce Heart Disease Risk Naturally: Diet, Exercise & Lifestyle Tips

Can You Be Fit And Still Be At Risk?

Regular exercise is beneficial for heart health, but doctors caution against treating gym habit as proof that the cardiovascular system is healthy. Exercising everyday is not enough to believe that your heart is completely healthy.

“Going to the gym does not automatically mean that a person has no cardiovascular risk. People can overlook smoking, family history, high cholesterol, blood pressure, or an unhealthy diet. Fitness should not be judged only by how much one can exercise,” Dr Khan said.

This is noteworthy for young adults who exercise intensely but do not know their blood pressure, blood sugar, or cholesterol levels. Dr Khan recommends a baseline health assessment with a family history of early heart disease or other risk factors before undertaking very intense training.

Also read: Stopping Ozempic, Wegovy, Mounjaro Linked To 22% Higher Heart Attack, Stroke Risk: Study

If You Are Going To Engage In Intense Exercise...

Dr Navasundi recommends that healthy young adults who are planning to begin intense gym training, marathon running or strenuous recreational activities undergo a comprehensive cardiovascular and lung-function test after consultation with a cardiologist.

Dr. Khan said, “A baseline health check is important, especially for someone with a family history or other risk factors. Blood pressure, blood sugar and cholesterol should be assessed, and any symptoms should not be ignored. It is better to understand your cardiovascular risk before starting very intense training.”

Depending on the person, a cardiologist may recommend tests like an ECG, echocardiogram, stress treadmill test, lipid profile, blood sugar and other investigations. In people with a strong family history of premature disease, further testing may sometimes be considered.

Also read: Preeclampsia May End With Pregnancy. Your Heart Risk May Not

Cardiologists Reveal An Alarming Heart Attack Pattern

Dr Navasundi says the biggest change he has observed over his three-decade career is the age at which heart attacks are occurring and the severity of disease in some young patients.

He said, “Compared to my early career I see much younger patients right from the age of 20 onwards having heart attacks and much larger number of heart attack patients. Patients are younger these days. At least 25% of my heart attack patients are less than 40 years of age and close to about 40% of our heart attack patients are less than 50 years of age.”

He also says he is seeing recurrent heart attacks in young people, multiple blockages and, in some patients in their 30s, three-vessel disease. He added, “Many young people are having severe damage during the very first heart attack compared to people in earlier years.”

Dr. Khan said that young cases are showing much earlier than they expected. She said, “I have been seeing this trend of heart attacks occurring in younger patients, sometimes nearly a decade earlier than what we traditionally expected, for the past 10 to 15 years. The increasing presence of risk factors such as smoking and unhealthy dietary habits in younger people is concerning.”

Three Things Young Adults Should Not Ignore

Dr Khan has three simple messages for people in their 20s and 30s: “First, age does not completely protect you from heart disease. Second, never dismiss chest discomfort as acidity without considering other possibilities. Third, know your family history and get a baseline health check, particularly if you smoke, have risk factors or are planning intense exercise.”

Dr Navasundi urges young adults to know their numbers, including blood pressure, heart rate, blood sugar and cholesterol, rather than simply being told that their results are “normal” or “abnormal”.

His final message is that heart health should not become a concern only after a cardiac event. He added, “So live with sense of vulnerability and responsibility to prevent heart disease in your early life. Know your family history, know your numbers.”

Waking up at night can make it difficult to fall back asleep, especially when the mind becomes alert and starts racing. Neuroscientist Andrew Huberman has suggested a simple eye-movement routine that he says may help people drift back to sleep. But does it actually work?

How Does Andrew Huberman’s Sleep Trick Work?

The routine is performed with the eyes closed:

• Slowly move the eyes to one side, then the other, followed by up and down.

• Trace a circle with the eyes, first counterclockwise and then clockwise.

• Point the eyes toward the nose and take a long exhale.

Huberman suggests repeating the sequence two to three times.

His theory is that the movements may interact with brain circuits involved in tracking the body's position, including pathways involving the eyes, brainstem and cerebellum.

Also read: Struggling With Sleep? Neurologist Shares 3 Simple Tips For Better Sleep Health

Sleep Experts Say The Idea Is Unproven

Shelby Harris, a psychologist and board-certified sleep expert, says there are reasonable grounds to try it, Women's World magazine reported.

“I think it’s a very reasonable thing to try. It’s free, low effort, carries essentially no risk and has solid reasons it could help,” Harris was quoted as saying.

She notes that sleep tends to become more fragmented with age.

“Sleep naturally becomes more fragmented with age, with less time in deep sleep and more time in the lighter stages where it’s easy to wake up,” Harris said.

Hormonal changes with age can also contribute to more fragile sleep in women. But a plausible explanation does not mean the technique has been proven.

Michael Grandner, a clinical psychologist and sleep researcher at the University of Arizona, told Inc.com that eye movements, balance signals, the brainstem and cerebellum all contribute to how the brain tracks the body's position in space.

However, he said he is “not aware of studies that have directly tested that chain of events, or clinical trials showing that this particular eye-movement exercise reliably shortens sleep onset.”

Brant Hasler, co-director of the Behavioral Sleep Medicine Training Program at the University of Pittsburgh School of Medicine, added that the technique does not resemble a validated behavioral sleep intervention.

A Relaxing Technique Not A Treatment

According to Grandner, the exercise may be better understood as a relaxation or focused-attention technique.

He said he would place it “closer to a relaxation, focused-attention, or mindfulness exercise than to an established treatment for insomnia.”

The repetitive movements could give the mind something neutral to focus on instead of worrying, planning for the next day or checking whether sleep has returned.

Further, Hasler said bedtime activities can be useful when they occupy the mind without becoming stimulating. The eye exercise could work in that way, he said, “regardless of any additional effects via proprioception.”

The slow breathing paired with the exercise may also help with relaxation.

It Could Backfire If You Try Too Hard

Hasler said expectancy effects could explain some positive experiences with the technique. Grandner also cautioned against repeatedly checking whether the trick is working.

If the exercise becomes another task to perform perfectly, “it could become another form of sleep effort, which can actually perpetuate insomnia,” he said.

Rabies is most often associated with dog-mediated transmission in humans, but the virus can infect a wide range of mammals. In 2026, unusual cases involving farm goats, beavers and Cape fur seals raised fresh questions about how rabies moves between species.

Since July 2026, multiple US jurisdictions have reported human rabies exposures involving known rabies vectors or animals in which rabies is less commonly reported. The CDC issued a health advisory on September 10 “in response to recent reports of increases in human exposures to rabid or possibly rabid animals.”

The concern is not limited to North America. At least 176 people had been bitten by rabid Cape fur seals along South Africa’s coastline by the end of 2025, while researchers have warned that the disease could spread to other marine mammal species.

In North Carolina in 2026, a wild skunk entered a pen containing baby goats, some of which later tested positive for rabies. Of the 284 people evaluated by local health departments, post-exposure prophylaxis (PEP) was recommended for 213. In Maryland, a 13-year-old boy was attacked by a beaver while swimming at a state park and required surgery for his injuries.

These cases raise a bigger question: Are unusual infections simply spillover from established rabies hosts, or can the virus establish sustained transmission in a new species? To understand this better, HealthandMe spoke to two experts.

Also read: US CDC Warns Of Rising Human Rabies Exposure Risk: How To Stay Safe

Are These New Rabies Hosts Or Spillover?

Dr Anish T S, Professor at the School of Public Health, Kerala University of Health Sciences, told HealthandMe that rabies can infect mammals, but an infected animal is not necessarily a reservoir host.

Genetic sequencing can help establish where an unusual infection came from and whether the virus is changing.

“So one thing that we can do is genetic analysis. If we are able to pick up these animals infected by rabies, we find what kind of rabies virus it is and do maybe a sequencing of the genome of this virus.”

“These kinds of analysis could be done still, but it is a question that whether this particular virus is changing its host or the virus is accumulating some kind of genetic mutations so that it can get maybe involved with some other animals. It can choose some other animals also as their host. It is actually a very pertinent question.”

The Cape fur seal cases add another dimension to this question, with sustained rabies transmission reported within the marine mammal population.

What Happens After Exposure?

Dr NK Ganguly, former Director General of the Indian Council of Medical Research (ICMR), told HealthandMe that rabies in goats is rare, while beaver exposures need particular caution.

“Beaver is one animal where we have to be very careful.”

Dr Anish said rabies can also present as paralytic or “dumb” rabies, which may not show classic signs and could lead people to handle or treat an infected animal without recognizing the risk.

Dr Ganguly stressed the need for prompt medical care after exposure.

“The rabies incubation period is around 10 days. So if somebody has been exposed, they should be immediately vaccinated. And if the exposure is with a bite or something at the upper limbs, then they need to be given an antiserum as well as vaccinated.”

“So depending on the exposure, you are given a vaccine which is available, and you are also given the cocktail of antibodies, the monoclonal antibodies, which act immediately.”

Why Wildlife And Livestock Surveillance Matters

Read More: Rabies Day Exclusive: ‘We Need To Target The Source’ For A Rabies-Free India By 2030, Says Veterinary Epidemiologist

Dr Ganguly said rabies can also circulate in wild and feral animals, including foxes, while cats and other species can also be infected.

He said surveillance should extend beyond dogs to domestic animals that are in close contact with them and to wildlife where feasible.

“Surveillance should include domestic animals also which are in close contact with the dogs.”

“There should be surveillance. There should be sentinel surveillance. We should carry out, if it is affordable.”

He also pointed to dog vaccination and sterilization, as well as bait vaccination for wildlife and stray animals.

Could The Virus Be Changing?

Dr Anish said unusual infections need investigation to determine whether they are isolated spillover events or linked to changes in the virus.

“The real issue is if the virus is changing much because of mutations. Because rabies virus is not that much notorious for mutations. That is why most of our vaccines are working.”

He said genetic studies could help answer whether existing vaccines and treatments would remain effective if significant mutations emerge.

“So the genetic studies of the virus may give us the answers to these questions.”

India’s Rabies Elimination Challenge

For India, the experts said the priority remains breaking established dog-mediated transmission chains before focusing on less common pathways.

“If you just look at the rabies situation in India, we are not even able to manage the pure dog-mediated rabies. That is, people are bitten by rabid dogs and people are getting infected, and we are not able to have maybe full coverage of vaccination, and all the other things are actually the biggest concern,” Dr Anish said.

Dr Ganguly added that surveillance should include domestic animals also which are in close contact with the dogs.

"But essentially, in the urban areas, the dog is the main animal, and we should—the Supreme Court has given now a lot of directions in this particular regard—that the dogs may be sterilized," the expert said.

The pet dogs need to be vaccinated and other stray dogs should be taken to facilities where they need to be sterilized and they need to be vaccinated, the experts said.