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.

The US Food and Drug Administration approved leucovorin for cerebral folate deficiency in the receptor 1 gene, a rare genetic condition. However, last year, in September, this drug was noted as the possible and potential treatment for children with autism. The Trump administration noted that Tylenol may be triggering autism in children when is consumed by pregnant mothers. The same conference touted this drug as a potential treatment, while not enough scientific evidence was there to support the claim. Yet, many parents looked for the prescription to support their children.

Health and Me also reported a story of a mother who looked for the drug for her three-year-old son. Another case of four-year-old Jose Morales-Ortiz, who struggled to speak even two-word sentences. As per a CNN report, he was diagnosed with severe autism and rarely responded when someone called his name.

However, something changed, in early summers, he began telling his guardian Keith Joyce about the conversation with his classmates and answering follow-up questions. For Keith, it was a moment of joy. It was also the first time Keith had a conversation with him.

Joyce believes the change began after Jose started taking leucovorin, a medication originally approved to reduce the side effects of certain chemotherapy drugs. Now, researchers are investigating whether the drug may help some children with autism—particularly those with a condition known as cerebral folate deficiency.

However, scientists caution that while early studies are promising, the evidence is still limited and the treatment remains controversial.

What Is Leucovorin?

Leucovorin, also known as folinic acid, is a biologically active form of vitamin B9 or folate. Unlike standard folic acid supplements, it does not require the body to convert it into an active form before it can be used. Due to this very feature, it can bypass certain metabolic steps and deliver folate more directly to the cells.

It is a high-dose B vitamin, which is commonly used as a treatment to counteract the side effects of chemotherapy. It has been approved by the FDA for cerebral folate deficiency in the receptor 1 gene. The disease is rare and fewer than 50 cases have been identified worldwide. FDA Commissioner Dr Marty Makary called this approval "a significant milestone" for patients with the condition.

Doctors have used the drug for several purposes, which also include:

• Reducing toxic side effects of chemotherapy
• Enhancing the effectiveness of certain cancer treatments
• Treating folate deficiency caused by medications or disease

Recently, scientists began exploring whether leucovorin could also help certain neurological conditions.

Read: Leucovorin Approved By FDA But For A Rare Genetic Disease, Not For Autism

What Role Does Folate Play In Brain Development?

Folate is essential for brain development and neural function.

It helps in:

• DNA synthesis and repair
• Formation of neurotransmitters
• Development of neural connections
• Cell growth in the developing brain

During pregnancy, folate is so critical that many countries fortify foods with folic acid to prevent birth defects such as neural tube defects.

However, in some children, the issue may not be a lack of folate in the diet—but a problem with how folate reaches the brain.

What Happens In Cerebral Folate Deficiency?

In 2005, researchers discovered an unusual phenomenon in some children with developmental disorders.

Although their blood folate levels were normal, their brain folate levels were extremely low.

The reason appeared to be autoantibodies—immune proteins that mistakenly attack the body’s own tissues. In this case, the antibodies targeted folate receptor alpha, the protein responsible for transporting folate across the blood-brain barrier.

When these receptors are blocked:

• Folate cannot enter the brain efficiently
• Neural development may be affected
• Symptoms similar to autism may appear

This condition is called cerebral folate deficiency.

Researchers also developed a diagnostic blood test called the Folate Receptor Autoantibody Test (FRAT) to detect these antibodies.

How Does Leucovorin Work?

It could work in such a case because it is able to bypass the blocked folate receptors. It does not rely on the usual transport system and is able to enter the brain through alternative transport pathways, which allow neurons to access the folate they need. Scientists also believe that this could improve neurotransmitter production, support neural communication, and enhance brain metabolism in certain children.

Some clinical studies have suggested that leucovorin may improve language and communication skills in certain children with autism.

In small trials:

• Some children showed improvements in expressive speech
• Others improved in receptive language and social communication
• Benefits appeared strongest in children with folate receptor antibodies

However, the results have been mixed.

Some studies have found only modest improvements, and large placebo-controlled trials—considered the gold standard in medical research—are still lacking.

Because autism is a complex spectrum condition with many biological pathways involved, researchers emphasize that no single medication is likely to work for every child.

The growing interest in leucovorin reflects a broader shift in autism research: looking for biological subtypes of the condition that might respond to targeted treatments.

If cerebral folate deficiency proves to be one of those subtypes, leucovorin could become an important therapy for a specific group of children.

But scientists emphasize that autism is highly complex. “There’s no autism pill,” many researchers say.

California made it news for a disease that has no vaccination. This is the human metapneumovirus or the HMPV. While some of the symptoms of this virus are similar to that of any common cold or influenza like cough, fever, nasal congestion or shortness of breath, there are several symptoms that are unique to the disease.

Unique Symptoms Of HMPV - The Virus Without Vaccine

Unlike mild common colds, HMPV often presents with a high-grade fever, particularly in children. Some of the other symptoms also include persistent coughing, including dry or productive and may persist for a long duration.

Furthermore, it could cause wheezing, difficulty in breathing, which could also lead to severe lower respiratory tract illness like bronchiolitis or pneumonia. In children and older adults, it could also cause severe or often fatal bronchiolitis or rapid-onset pneumonia.

In infants, it could also exhibit irritability, poor feeding, or dehydration.

Other symptoms, which could resemble common cold like symptoms are:

• cough
• fever
• sore throat
• runny or stuffy nose
• body ache
• headache

What Is Happening In California?

As per the public database WasterwaterScan Dashboard, high levels of HMPV were detected across Northern California cities. The highest levels were reported in Redwood City, whereas elevated levels were found in San Francisco Bay Area and Napa's Wine Country. What's more dangerous is that this virus is without a vaccine.

The good news is that in other parts of country HMPV remains lower. However, the Centers for Disease Control and Prevention (CDC) noted that data from October 2025 shows the cases are trending up, especially during winter and spring.

Read: Virus Without Vaccine Hits California; No Need To Worry, Say Public Health Officials

Dr. Matthew Binnicker, director of the Clinical Virology Laboratory at Mayo Clinic, as reported by The Independent said, "In the late winter, early spring, it can account for five percent to 10 percent of all the respiratory infections that we diagnose in the United States. So it's definitely out there." Experts explain that other viruses like HMPV or influenza get a chance when COVID is quieter.

What Is HMPV - The Virus Without Vaccine?

HMPV was first discovered in 2001 and is part of the Pneumoviridae family along with the Respiratory syncytial virus (RSV).

HMPV most likely spreads from an infected person to others through:

• the air by coughing and sneezing
• close personal contact, such as touching or shaking hands
• touching objects or surfaces that have the viruses on them, then touching the mouth, nose, or eyes

In the US, HMPV circulates in predictable patterns each year, typically beginning in winter and lasting through spring.

Who Are At Risk Of HMPV?

People at risk include:

• elderly people
• children
• people with comorbidities

"The HMPV is not deadly, and there is no evidence of mortality or a severe transmission rate," former Indian Council of Medical Research (ICMR) scientist, Dr. Raman Gangakhedkar, told IANS, during the virus's outbreak in India in 2025.

“The virus may cause pneumonitis-like illness, but the mortality rates are almost unknown so far. HMPV has a global prevalence of about 4 per cent,” he added.

Smoking has been long recognized as one of the worst habits a person can have, and Dr Jeremy London agrees with this statement. Dr. London, a cardiovascular surgeon, in a recent interview with Mel Robbins revealed that his number one advice as a heart doctor is to avoid smoking.

“I cannot come up with one single thing that does as much damage to every organ in the body as smoking cigarettes. And look, it's incredibly addictive and I know that and I pass no judgment because I know how difficult it is.”

He explained that in his practice he has dealt with chronic smokers for years and still believed that it is the single most dangerous thing one can do to themselves.

Also Read: Why Is It Harder For Women To Quit Smoking?

How Does Smoking Affect Other Organs?

Emphasizing how this one habit affects all organs in our body, Dr London mentioned the well-known link between lung cancer and smoking.

However, there are many more chronic diseases associated with the rest of the body that can develop due to smoking apart from lung conditions, according to the American Lung Association.

Here is what you should keep an eye out for:

Heart Disease

Also Read: 3 Science-Backed Methods To Quit Smoking For Good

Asthma

Reproductive Health

Vision Loss

Lung Cancer

Smoking is the leading cause of lung cancer, accounting for nearly 90 percent of all cases. Although medical treatments have improved, the five-year survival rate remains low. Quitting is the most effective way to lower your risk of this deadly disease.

Chronic Obstructive Pulmonary Disease

Other Cancers