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.

After the social media trend of ‘ferritin face’ had everyone scrutinising their face for pale skin, dark circles and sluggish features due to low iron levels, attention is now shifting to hair. Described as ‘ferritin hair’, social media users have been attributing symptoms like unusual hair shedding, thinning and brittle strands to the body’s low iron stores.

The trend is not just a fluke. There is a medical basis for recognising iron deficiency in people facing hair loss. However, ‘ferritin hair’ is not a formal medical diagnosis. Hair loss can be due to several reasons, including hormonal changes, stress, thyroid disorders, nutritional deficiencies and genetic hair-loss conditions.

So is there a connection between ferritin and hair health and which signs should prompt someone to seek medical advice?

What Is Ferritin And How Is It Connected To Your Hair?

Also read: Botox And Fillers: UK Watchdog Says Clinics Should Check Mental Health Before Injecting

Ferritin is a protein that stores iron in the body and releases it when needed. A blood ferritin test helps assess the body's iron reserves. Iron is essential for several functions, including the production of haemoglobin, which carries oxygen in the blood.

When iron stores are exhausted, the body prioritises essential functions over those that are not absolutely necessary for survival. Hair growth may be affected in some people, contributing to increased shedding.

A 2023 clinical review published in Cutis noted that measuring serum ferritin can be useful while evaluating people with diffuse hair loss, especially to identify underlying iron deficiency.

A 2026 study published in Cureus reported that low serum ferritin and telogen effluvium in women may be connected.

A separate systematic review published in 2026 also found lower ferritin levels among people with telogen effluvium.

The European Food Safety Authority has also observed a cause-and-effect relationship between iron intake and the maintenance of normal hair growth.

Possible Signs Of 'Ferritin Hair'

Also read: Ditching Dairy For Oat, Almond Milk? Your Body Could Miss Out On These 4 Essential Nutrients

Hair shedding: One possible sign is diffuse hair shedding, in which more hair than usual falls from across the scalp rather than from one specific area. This can occur due to a condition called telogen effluvium, in which more hair follicles than usual enter the resting phase of the hair-growth cycle.

Hair thinning: Constant shedding can make the hair appear less dense over time. Some people may notice a wider-looking parting or thinner volume.

Dry or brittle hair: Iron deficiency may cause dry, brittle hair. However, hair texture can also be affected by heat styling, chemical treatments and other nutritional factors.

Other symptoms: Hair shedding may occur with other signs of iron deficiency like fatigue, weakness, poor concentration, breathlessness, palpitations or pale skin.

Causes Of Iron Deficiency Or Low Ferritin Levels

Iron deficiency can develop when the body loses more iron than it absorbs and does not receive enough through diet. Heavy menstrual bleeding and pregnancy are common reasons for iron deficiency. Other possible causes include:

• Inadequate dietary iron: People who do not consume enough iron-rich foods are at risk if their diets are restrictive.
• Poor absorption: Conditions such as coeliac disease can interfere with the absorption of iron.
• Blood loss: Gastrointestinal conditions like gastritis and intestinal polyps can sometimes lead to iron loss.
• Increased requirements: Pregnancy can demand increased iron needs.

Delhi’s air pollution has worsened even before the onset of peak winter. This has raised concerns about development and health of children who are constantly exposed to high levels of fine particulate matter (PM2.5).

While the immediate effects of polluted air like coughing, wheezing and breathing difficulties are known, research says that long-term exposure can also impact children’s developing brains, including effects on their memory, attention, IQ and ability to learn.

Delhi Winter Pollution Highest In 3 Years

On November 12, Delhi's air quality got listed under 'very poor' category. Stations like IIT Delhi and Delhi IITM recorded an AQI of 416, while NSUT Jaffarpur and Delhi DPCC recorded 404. Anand Vihar station recorded 319 while DTU Delhi stated 372.

A new analysis by the Centre for Science and Environment (CSE), released recently, found that Delhi’s average PM2.5 concentration during the week preceding Diwali stood at 236 micrograms per cubic metre (µg/m³), the highest in the last three years. This was 97% higher than the 120 µg/m³ recorded in 2025 and 32% above the 179 µg/m³ recorded in 2024.

The analysis also found that pollution levels during the early winter period were higher this year than in 2025. Vehicular emissions and pollution from neighbouring NCR districts were among the major contributors. The findings suggest that firecracker smoke from Diwali aggravated an already high pollution burden.

Delhi’s pollution crisis is not only threatening people’s lungs and cardiovascular health, it is also posing significant risks to children’s brain health. Could breathing polluted air affect how well children concentrate, recall information and learn at school?

Also read: World Pneumonia Day 2026: Post-Diwali Cough Or Pneumonia? Doctors Explain Warning Signs

Effects Of PM2.5 On Children’s Cognitive Health

PM2.5 refers to fine particulate matter with a diameter of 2.5 micrometres or smaller. These particles are small enough to travel deep into the respiratory system, fueling inflammation and oxidative stress. Not just lungs, their effects may reach children’s nervous systems.

Dr Sushil Singla, Director, Paediatrics, Sarvodaya Hospital, Sector 8, Faridabad told HealthandMe, “Exposure to PM2.5 (fine particulate matter) can affect children's cognitive development, including memory, attention span and learning abilities. These tiny particles can penetrate deep into the lungs and may trigger inflammation and oxidative stress, which can have wider effects on the developing brain. Children are particularly vulnerable because their brains are still developing and they inhale more air relative to their body weight than adults.”

The developing brain goes through significant changes throughout childhood. Processes involved in learning, memory, attention and executive function continue to evolve during these years. Exposure to environmental pollutants during fragile developmental periods is therefore a huge concern.

Also read: Delhi Air Pollution: PM2.5 Exposure May Raise Type 2 Diabetes Risk By 16%, Study Finds

Effects On Learning And Academic Performance

Difficulties in paying attention, memorising and processing complex information can make it harder for children to follow lessons in the classroom.

“Prolonged exposure to high levels of air pollution has been associated with difficulties in concentration, attention, information processing and memory. This may also affect a child's learning abilities and academic performance over time. Although the extent of the impact varies depending on the duration and intensity of exposure, parents should take preventive measures,” says Dr Singla.

What Does Science Say?

Also read: Delhi Breathes Toxic PM2.5: Study Finds 9 Million Lives Could Be Saved Globally By Meeting WHO Air Quality Limits

Several studies suggest that air pollution exposure may be associated with poorer cognitive outcomes in children.

A review and meta-analysis published in Environmental Health in 2024 examined six studies involving 4,860 children across North America, Europe and Asia. It found a statistically significant association between higher PM2.5 exposure and lower IQ scores. The researchers reported that every 1 µg/m³ increase in PM2.5 was associated with a 0.27-point decrease in full-scale IQ.

A 2022 review of 86 studies also found evidence between particulate matter exposure and poorer executive function in children, specifically working memory. Executive function refers to a set of mental skills that help children plan, focus attention, remember instructions and manage multiple tasks.

Recent research based on data from the US Adolescent Brain Cognitive Development (ABCD) study also showed that PM2.5 exposure was linked with smaller hippocampal volumes and lower working-memory in young people.

The hippocampus is a brain region involved in learning and memory. The researchers suggested that exposure during both prenatal development and late childhood could affect brain structure and function.

What Can Parents Do?

While individual precautions cannot eliminate the pollution burden, they can help reduce exposure. Dr Singla advises parents to monitor AQI levels, limit outdoor activities during peak pollution hours and ensure adequate indoor ventilation. Other measures include:

• Check air quality before outdoor activities: Avoid outdoor sports, running and strenuous exercise when pollution levels are high.

• Keep windows closed during pollution episodes: Ventilate rooms when outdoor air quality improves. Where possible, use an air purifier with a HEPA filter.

• Use a well-fitting N95 mask: A respirator can reduce exposure to particulate matter when children need to be outdoors.

• Follow school advisories: Parents should stay informed about changes to outdoor classes, sports and school schedules during severe pollution days.

Former US President Joe Biden has shared an update on his battle with stage 4 prostate cancer, saying the disease has sometimes slowed him down but has not stopped him.

In a post on X, ahead of the November 17 release of his memoir, PROMISE ME, AMERICA, Biden revealed that he was diagnosed with prostate cancer while writing the book.

“Some days are better than others. It hasn't stopped me. But sometimes it slows me down,” he wrote, adding that he would be unable to participate in as many book-related conversations as he had hoped.

Biden said his doctors were encouraged by his response to treatment. He also thanked people for their prayers and wishes, saying their support meant a great deal to him, Jill and their family.

Biden also discussed his cancer diagnosis, treatment and its impact on his life in an interview with People, alongside his wife, former First Lady Jill Biden.

Joe Biden: Would Have Resigned If He Had Known About Cancer

Also read: Over 40% Prostate Cancer Patients in India Diagnosed After Cancer Has Spread: ICMR study

Biden addressed speculation about when he learnt about his diagnosis, saying, “We let the public know when I found out.”

He said he initially experienced recurring pain, prompting Jill to question why men in their 70s were not routinely tested. Subsequent tests revealed that his prostate cancer had metastasised to the bone.

Biden also said he would have stepped down from the presidency had he known his discomfort was caused by cancer, People reported.

“If I had known that I was feeling lousy because I had cancer, I would have resigned,” he said, adding that he did not believe an 80-year-old man with cancer should be running for president.

The diagnosis changed the couple's plans for life after the White House, including travelling.

“Because of that metastasis, he will always have cancer,” Jill said. “It changes your life, it changes your perspective about life. So now we're on a new journey.”

Biden said he remained hopeful and was feeling good. He takes eight pills a day and has undergone two tests to check whether the cancer has spread further. He said the results indicated that it had not.

“I still have all my faculties. I still have my physical faculties as well. So we're hopeful,” he said.

Jill Biden On The Challenges Of Caregiving

Read More: Minimally Invasive Focal Therapy For Prostate Cancer Promises Fewer Side Effects Than Surgery Or Radiotherapy

Meanwhile, Jill described the emotional and physical demands of caring for her husband, saying it was different from looking after her parents or in-laws.

“It's just a lot different, I think, when it's your spouse because of the difference in the relationship,” she said.

Her daily routine now includes ensuring Biden eats well, exercises and takes his medication, as well as communicating with his doctors.

“I have seen how hard it is, how really emotionally hard it is, physically hard to go through each day,” she said.

The couple also discussed their family life and time with their grandchildren as they approach their 50th wedding anniversary.

What Is Prostate Cancer?

Prostate cancer develops in the prostate, a gland found only in males, located below the urinary bladder and in front of the rectum.

Nearly all prostate cancers develop from glandular cells and are classified as adenocarcinomas.

In 2020, an estimated 1.4 million new cases and 370,000 deaths from prostate cancer were reported worldwide. It was the most frequently diagnosed cancer among men in 112 countries and the leading cause of cancer deaths among men in 48 countries.

According to the US Centers for Disease Control and Prevention (CDC), 255,395 new prostate cancer cases were reported in the US in 2022, making it the most commonly diagnosed cancer among American men that year.

What Are The Symptoms Of Prostate Cancer?

Symptoms may include:

• Blood in the urine or semen
• Difficulty urinating
• Erectile dysfunction
• Bone pain
• Unexplained weight loss.