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.

Menopause is not just the end of fertility or a gradual part of aging. It may trigger an abrupt, and rapid, “cliff-like” biological shift across multiple body systems, including the bones, liver and blood fats, a study has found.

Menopause is a natural stage of aging that ends menstruation and reproductive function. It usually occurs between ages 45 and 55.

It marks the permanent end of menstruation as ovarian follicles are depleted, leading to changes in several sex hormones. The research, published in Nature Medicine, found that some hormonal changes begin more than a decade before the final menstrual period.

The findings suggest that menopause is a distinct, body-wide physiological transition rather than simply a gradual part of aging. Comparable changes were not observed in men, prompting the researchers to describe the transition as a step-like physiological “cliff.”

Dr. Mia Schaumberg, an associate professor of physiology at the University of the Sunshine Coast, said the findings revealed a large “jump,” or change, at menopause that appeared like a “cliff” or “step” and progressed beyond “normal” aging, as represented by the male cohort.

What Did The Study Find?

Also read: Can Menopause Be Delayed? What Science Says About Slowing Ovarian Aging

Menopause has been linked to changes across multiple biological systems. However, establishing when these changes occur has been difficult because the final menstrual period is rarely recorded and long-term studies are relatively small.

To investigate these changes, a team at the Weizmann Institute of Science in Israel developed a computational method to reconstruct physiological changes around the final menstrual period.

The researchers analyzed more than 300 million laboratory tests from over 1 million women in the United States and Israel, covering the period from 1999 to 2024.

Across both datasets, the researchers observed abrupt changes in multiple body systems around menopause. In the US dataset, 52 of 90 laboratory tests showed statistically significant abrupt changes. These included measurements related to sex hormones, bone health, liver and kidney function, blood chemistry and blood fats.

Hormonal Changes Begin Over A Decade Early

Read More: ‘I Was Vocal About Cancer But Silent About Menopause Out Of Shame’, Says Actress Lisa Ray

The study found that three sex hormones began changing rapidly more than a decade before the final menstrual period:

• Anti-Müllerian hormone (AMH): Declined rapidly around 15 years beforehand.
• Follicle-stimulating hormone (FSH): Increased rapidly around 14 years beforehand.
• Estradiol: Changed around 12 years beforehand.

These findings suggest that hormonal changes associated with menopause begin much earlier than the final menstrual period and may precede broader physiological changes.

How Does Menopause Affect Bones, Liver And Kidneys?

The physiological changes were not limited to sex hormones such as estrogen. They were also detected in laboratory tests reflecting the function of other bodily systems, including the bones and kidneys.

“The postmenopausal results pointed toward poorer health outcomes,” Dr. Schaumberg said.

The researchers noted that the systems showing the most significant changes, including bone health and the liver, are particularly sensitive to estrogen. In contrast, systems with weaker known links to estrogen did not show detectable changes of the same kind.

Why Experts Disagree?

Australian experts urge caution interpreting the results. Martha Hickey, head of menopause services at The Women's Hospital Victoria who was not involved in the study, described the claim of "cliff-like" changes across multiple body systems as "unnecessarily alarming" for women.

"Physiological cliff is not a scientific or medical term," she told ABC News.

Sydney-based general practitioner Elina Safro, who chairs the education subcommittee of the Australasian Menopause Society, also agreed.

"My reading is that the 'cliff' theory is not plausible," she said.

Can Menopausal Hormone Therapy Help?

The study found that menopausal hormone therapy (MHT), also called hormone replacement therapy (HRT) and replaces estrogen and progesterone, was associated with smaller changes in several measures, particularly those related to bone, liver and kidney function.

The authors suggested that this finding could indicate a protective effect of MHT on certain bodily systems, including the skeletal system. But more research is needed to establish it.

A study of more than 700 individuals found distinct differences in the mix of bacteria in the mouths and lungs of those with severe long COVID.

Published in the European Respiratory Journal, the study found that differences in the lung microbiome were linked to respiratory problems, cognitive difficulties and digestive symptoms associated with long COVID.

The findings may help researchers understand why some people develop long COVID and identify potential treatments, according to the team from the University of Dundee, UK.

"The microbiome is important to maintain health throughout the body, so it is a strong candidate for something that may contribute to long COVID,” said lead author Dr. Daniela Alferes de Lima Headley.

What Did The Study Find?

Also read: XFG COVID Variant: What India Should Watch As Cases Rise In UK And France

The observational study included 771 adults who had been hospitalized for COVID-19 between February 2020 and March 2021. Researchers grouped participants according to the severity of their ongoing health problems and symptoms.

The participants had an average age of 57.5 years, and 38.5% were women.

Six months after hospital discharge, researchers collected saliva samples to examine microbes in the mouth and sputum samples to study the lung microbiome. They used DNA sequencing to identify the microbes and analyze their diversity. Participants also completed questionnaires about their symptoms.

The results showed that people with very severe long COVID had distinct differences in their oral and lung microbiomes compared with those who had fewer ongoing symptoms.

Microbiome differences were also associated with:

• • Respiratory problems: Reduced lung function.
  • Cognitive symptoms: Brain fog, memory problems, and difficulty with attention and concentration.
  • Digestive issues: Abdominal pain, nausea, diarrhea and loss of appetite.

Bacterial Changes Linked To Inflammation

Further, the changes associated with long COVID symptoms also included an increased abundance of bacteria that produce lactic acid. These changes were also linked to signs of inflammation in participants' blood samples.

James Chalmers, chair of respiratory research at the University of Dundee, said the greatest microbiome changes were found in people with the most severe symptoms five to six months after COVID-19.

"We also found that changes in the airway microbiome were linked not just to lung problems, but also to symptoms like brain fog and gut symptoms, suggesting the lung microbiome could have effects on health more broadly," he added.

However, the researchers do not yet know whether these microbiome differences existed before COVID-19 or developed after infection. The long-term effects of these changes also remain unknown.

Read More: COVID-19 May Raise Risk of 6 Allergic Conditions, Study Finds

Could The Findings Lead To New Treatments?

Chalmers said more research is needed to understand what causes long COVID, which continues to affect many people worldwide.

Because the microbiome can be altered through interventions such as antibiotics and probiotics, understanding its role could help researchers explore potential treatment options.

What Is Long COVID?

Long COVID refers to new, returning or ongoing health problems that persist four or more weeks after the initial COVID-19 infection. Symptoms can last for months or even years.

Common symptoms include fatigue, brain fog, memory problems, difficulty concentrating and slowed thinking.

Research has also suggested that brain inflammation may persist even after the virus is no longer detectable.

For some women with endometriosis, getting a diagnosis is only the beginning of a long struggle to access treatment and navigate management.

In Canada, long waitlists for specialist appointments are pushing patients to consider expensive surgery abroad, highlighting how delays in care can prolong pain and disrupt everyday life.

Noelle Menu, 37, from Calgary, said her symptoms intensified after she stopped taking birth control while trying to conceive at 26.

Years of pain, emergency room visits, surgery and delays in specialist care eventually led her and her husband to seek private treatment in Tijuana, Mexico.

After being told that waiting several years to see a specialist in Canada was possible, Menu said: “We can’t deal with it in Canada.”

The couple used their savings and went into debt to pay for treatment at EndoGlobal in Mexico. The total cost was approximately $35,000, including travel, accommodation and other expenses, according to CBC News.

Her experience highlights the delay in addressing endometriosis that can intensify debilitating symptoms.

What Is Endometriosis And Why Can It Be Difficult To Diagnose?

Endometriosis is a chronic condition in which tissue similar to the lining of the uterus grows outside it, potentially affecting the ovaries, bowel, bladder and other areas. The resulting inflammation and scar tissue can cause severe menstrual cramps, persistent pelvic pain, painful sex, bowel or urinary symptoms and difficulties conceiving.

The World Health Organization estimates that endometriosis affects around 10% of reproductive-age women worldwide, or approximately 190 million people.

Diagnosis can be challenging because symptoms vary and may overlap with other conditions. There is no single definitive test that identifies every case. Doctors may use a detailed medical history, pelvic examination, ultrasound or MRI, with surgery sometimes needed to investigate or treat suspected disease.

The WHO estimates that diagnosis commonly takes between four and 12 years, leaving many patients managing symptoms without a clear explanation for prolonged periods.

Also read: Endometriosis: Repurposed Anti-Parasite Drug Shows Promise In Mouse Study

How Do Delays Affect Patients?

For patients with severe disease, waiting for specialist care can mean continuing to live with pain that interferes with work, relationships, sleep and fertility plans.

Another Canadian patient, identified in CBC's report as Papiernik, described discovering that endometriosis had infiltrated her colon after a colonoscopy detected a mass. She was referred for specialist care but faced further waits for an appointment and surgery.

“Living like this for two years was just not an option for me,” she said.

Canada's House of Commons health committee has identified gaps in endometriosis care, while the condition's economic impact includes lost productivity and healthcare costs. The issue is not simply whether treatment exists, but whether patients can access appropriate care before symptoms and complications become harder to manage.

Also read: Urine & Vaginal Samples May Help Detect Womb Cancer: Lancet Study Suggests Less Invasive Way To Triage Patients

Does Surgery Cure Endometriosis?

Surgery can remove endometriosis lesions, adhesions and scar tissue, reducing pain and treating complications. However, it is not a guaranteed cure. Symptoms may persist or return, and treatment decisions depend on disease severity, the organs involved, fertility goals and previous treatment.

Hormonal medicines and pain management can also help control symptoms. Some patients benefit from a combination of medical treatment, surgery and ongoing follow-up.

Travelling abroad may offer faster access to specialist treatment, but it comes with financial costs and other challenges. Patients should consider the surgeon's experience, the facility's standards, the possibility of complications and arrangements for follow-up after returning home.