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When talking about fertility in routine practice, we usually refer to the World Health Organization’s guideline of roughly 15 million sperm per millilitre (and around 39–40 million total per ejaculate) as the lower boundary of “normal.”
But the count alone doesn’t tell the full story. The quality of sperm, their motility, shape, and the couple’s overall reproductive health are equally important. We got in touch with Dr. Meenakshi Priya, Clinical Director & Fertility Specialist, Nova IVF Fertility, Coimbatore, who told us more about the same.
Dr Meenakshi said, “Think of sperm count like lottery tickets. More tickets (higher count) give you better odds, fewer tickets lower your chances — but even one well-functioning ticket (a motile, properly shaped sperm) can win.”
That’s why fertility clinics look at several factors: concentration, total number, progressive motility (whether sperm swim forward), and morphology (shape). The WHO manual provides the standard method and cut-offs used worldwide in labs, serving as the referee for semen analysis.
However, numbers matter clinically. Research over decades shows fertility starts to drop gradually below about 40 million/ml (or in older studies, 40 million total per ejaculate was a useful marker). The WHO threshold of 15 million/ml marks the lower edge of normal — values between 15 and 40 are a “grey zone,” where conception is possible but may take longer. So a man with 12 million/ml isn’t infertile, but the couple might need help like IUI or IVF depending on other factors.
But don’t get fixated on one number. A “normal” semen report is a combination of factors:
• Concentration ≥15 million/ml
• Total sperm count ≥39–40 million per ejaculate
• Progressive motility roughly >30%
• Normal morphology about 4% (Kruger criteria)
Lifestyle and health have a big impact on sperm. Smoking, heavy drinking, extra weight, prolonged heat exposure (saunas, hot tubs, tight underwear), certain medications, recent fevers, and conditions like varicocele or hormonal imbalances can all lower the numbers.
The good news? Most of these are reversible. Dr Meenakshi said, “Quitting smoking, reducing alcohol, losing a bit of weight, avoiding hot tubs for a few months, and treating infections can improve sperm.” Remember, sperm take time to renew but it usually takes 2–3 months of healthier habits for improvements to appear in a report. Be patient; your body is making changes even if you don’t see results immediately.
If semen analysis repeatedly shows very low sperm (oligozoospermia), no sperm (azoospermia), poor motility, or if a couple has been trying for a year (or six months if the woman is over 35) without success, it’s time to consult a specialist. One abnormal test isn’t the final word — tests are usually repeated, and a more thorough assessment may include hormone checks, ultrasounds, or genetic tests if needed.
Dr Meenakshi said, “Sperm count gives a headline, not the full story. It’s a useful screening tool, but fertility decisions are personal. If you’re concerned, get a proper semen analysis and speak with a fertility specialist — many fertility issues are treatable, and acting early makes a real difference.”
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Norovirus, often called the stomach bug, has returned. Between August 1 and December 11, health officials recorded 268 norovirus outbreaks, with numbers climbing steadily as winter travel increases and more people spend time indoors. The virus triggers stomach-related symptoms such as nausea, vomiting, diarrhea, and abdominal pain or cramping.
Some people also develop fever, headaches, and body aches. Although case numbers are not rising as sharply as flu, doctors remain concerned because norovirus spreads extremely easily. Making matters worse, norovirus is difficult to kill. Many of the common precautions used against flu and COVID offer little protection against this so-called winter vomiting bug.
Norovirus is among the most infectious viruses doctors deal with. “It can tear through a household and then circle back, with people repeatedly passing it to each other,” says Amy Edwards, MD, associate professor of pediatrics at Case Western Reserve University School of Medicine in Cleveland, Ohio, who specializes in infectious diseases. “It also spreads very quickly in crowded, closed settings like cruise ships.”
While contaminated surfaces can transmit norovirus, doctors say person-to-person spread is most common. An infected person can pass on the virus even before symptoms appear, throughout the illness, and after they start to feel better, Jennings warns.
For most people, norovirus symptoms ease within a few days, according to Jennings. However, the illness can be more serious for those with weaker immune systems, including young children, older adults, and people with certain health conditions.
If you think you have norovirus, focus on staying well hydrated. Ongoing vomiting can quickly lead to fluid loss and electrolyte imbalance. To prevent nausea from getting worse, Jennings recommends taking small sips of clear fluids like water, ginger ale, or coconut water.
Most importantly, seek medical care right away if you become dehydrated or if diarrhea lasts for weeks. Fischer explains that dehydration may cause sunken eyes, less frequent urination, dry skin and mouth, and extreme tiredness.
Norovirus symptoms often come on suddenly and may include:
Symptoms usually begin 12 to 48 hours after exposure and last for one to three days. Even after recovery, people can continue shedding the virus in their stool for weeks. In some cases, especially among those with other medical conditions, shedding can continue for months. Some people infected with norovirus never develop symptoms at all. Even so, they can still spread the virus to others.
Norovirus spreads very easily from one person to another. Because it is highly contagious, an infection can pass quickly through homes, schools, or other shared spaces. The virus is released through stool and vomit, and a person can spread it from the moment symptoms begin until several days after they feel better. Norovirus can also survive on surfaces and objects for days or even weeks.
You can catch norovirus by:
Norovirus is especially hard to get rid of because it can survive extreme hot and cold temperatures and is resistant to many common disinfectants.
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The NHS has issued fresh advice for people taking a widely prescribed medicine used to manage heart and circulation conditions. Across the UK, millions rely on beta-blockers to treat heart and blood vessel problems. Each year, more than 50 million prescriptions are written for these drugs, which help manage issues ranging from high blood pressure and abnormal heart rate to certain conditions affecting the brain and nervous system. Doctors most commonly prescribe bisoprolol, which NHS England lists as the seventh most prescribed medicine in the country.
Bisoprolol, sold under brand names such as Zebeta, Bisotab, and Concor, belongs to a group of medicines called beta-blockers. It is mainly used to treat various heart-related conditions by slowing the heart rate and relaxing blood vessels. This reduces strain on the heart and helps it pump blood more efficiently, according to the CDC. The NHS also explains that bisoprolol is used to prevent chest pain caused by angina and to manage atrial fibrillation and other irregular heart rhythms. By slowing the heart, it allows the heart muscle to work more effectively.
Data from 2024–25 shows that bisoprolol was dispensed around 32 million times in England alone. The NHS notes that for people with high blood pressure, taking bisoprolol can help lower the risk of future heart disease, heart attacks, and strokes.
Like most medicines, bisoprolol can cause side effects, and patients are advised to stay alert to them. People starting the medication are often told to take their first dose at night, as it can make some feel dizzy. There are several common side effects that affect more than one in 100 people. According to the NHS, these are usually mild and tend to settle over time. They include:
However, there are less common but more serious side effects that should not be ignored, as they may require urgent medical attention. The NHS advises contacting a doctor or calling 111 if:
The NHS also urges people to seek immediate help if certain symptoms appear. These include:
Emergency services should be contacted straight away if there are signs of a severe allergic reaction, known as anaphylaxis. The NHS says to call 999 immediately if:
The NHS stresses that while bisoprolol is effective and widely used, knowing when side effects are harmless and when they signal an emergency is key to staying safe.
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Rabies is a fatal viral disease that spreads to humans through the saliva of infected animals. It targets the central nervous system, and nearly 99 percent of human cases are linked to infected dogs. A recent *Lancet* study found that about 5,726 people still die from rabies each year, even though overall deaths have declined over time. This is why prompt medical care after a dog bite or scratch is critical. Most people believe the rabies vaccine taken after a bite is enough. What many do not realise is that a pre-exposure prophylaxis vaccine is also available and can be taken even before a bite occurs. So why does this vaccine matter, and how does it actually protect you?
A rabies pre-exposure prophylaxis, or PrEP, vaccine involves a set of shots given before any possible contact with the rabies virus. It is mainly recommended for people at higher risk, such as veterinarians, animal handlers, laboratory workers, and travellers visiting regions where rabies is common. While PrEP does not remove the need for treatment after a bite, it makes post-exposure care simpler. People who have received PrEP need fewer follow-up injections and do not require rabies immunoglobulin, which can be hard to access in emergencies and may save crucial time.
According to Dr Deepa Aggarwal, who shared insights on her Instagram account, the rabies pre-exposure prophylaxis vaccine prepares the immune system in advance. It helps the body develop antibodies before any exposure occurs. If a vaccinated person is bitten later, they need only two booster shots and no immunoglobulin. The immune response is quicker, lowering the risk of the virus spreading to the brain. This is especially important for people at high risk or in situations where medical treatment may be delayed.
The Advisory Committee on Immunization Practices, or ACIP, has updated its recommendations for rabies PrEP.
While the vaccine can benefit anyone, rabies pre-exposure prophylaxis is mainly advised for people with frequent or high risk of exposure. This includes veterinarians, animal handlers, wildlife workers, laboratory staff, and travellers to areas where rabies is widespread. The vaccine makes treatment after a bite easier by reducing the number of shots required. However, health authorities stress that while PrEP offers protection, it does not replace full post-exposure treatment after a confirmed bite, as advised by the CDC and WHO.
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