HealthPont

Ο περισσότερος ύπνος τις ημέρες που δεν εργαζόμαστε μπορεί να μειώσει την υπνηλία, αλλά δεν λειτουργεί σαν πλήρης διαγραφή μιας εβδομάδας με ανεπαρκή ξεκούραση. Τι δείχνουν οι μελέτες για το «χρέος ύπνου», την αποκατάσταση και το social jet lag; Από τη Δευτέρα έως την Παρασκευή, το ξυπνητήρι χτυπά νωρίς, οι υποχρεώσεις τελειώνουν αργά και ο ύπνος είναι συχνά το πρώτο πράγμα που περιορίζεται. Όταν έρχεται το Σαββατοκύριακο, η αυθόρμητη λύση είναι να κοιμηθούμε όσο περισσότερο μπορούμε, με την ελπίδα ότι θα αναπληρώσουμε τις ώρες που χάθηκαν μέσα στην εβδομάδα. Η ιδέα φαίνεται λογική, αλλά ο ανθρώπινος ύπνος δεν λειτουργεί ακριβώς σαν τραπεζικός λογαριασμός. Ο επιπλέον ύπνος μπορεί να προσφέρει πραγματική, βραχυπρόθεσμη ανακούφιση και να βελτιώσει ορισμένες πλευρές της εγρήγορσης και της διάθεσης. Δεν υπάρχουν, όμως, επαρκή στοιχεία ότι δύο μεγάλοι ύπνοι μπορούν να αναιρέσουν πλήρως τις γνωστικές, μεταβολικές και κιρκάδιες επιδράσεις μιας επαναλαμβανόμενης εβδομαδιαίας στέρησης ύπνου. ...

Sleeping longer on days off may reduce sleepiness, but it does not act as a complete reset after a week of insufficient rest. What does the evidence say about sleep debt, recovery and social jet lag? From Monday to Friday, the alarm rings early, responsibilities end late and sleep is often the first thing to be reduced. When the weekend arrives, the instinctive solution is to sleep for as long as possible in the hope of recovering the hours lost during the week. The idea sounds reasonable, but human sleep does not work exactly like a bank account. Extra sleep can provide genuine short-term relief and improve some aspects of alertness and mood. There is not, however, sufficient evidence that two long nights can fully reverse the cognitive, metabolic and circadian effects of repeatedly insufficient sleep during the working week. What Is Sleep Debt? Sleep debt describes the accumulated difference between the amount of sleep a person needs and the amount they actually obtain. If someon...

Sponsored content by OLDSPELL Sleep, food, movement and micronutrients all influence how alert we feel. What actually helps—and when does fatigue deserve medical attention? For many men, the day begins with coffee and continues with another cup when concentration starts to fade. In a schedule filled with work, commuting, family responsibilities and exercise, caffeine can seem like the quickest answer to tiredness. Daily energy, however, does not work like a switch that can be turned on with a single drink. How alert we feel is shaped by sleep, the timing and composition of meals, hydration, movement, stress and the overall structure of the day. Micronutrients also support normal processes in the body, but that does not mean that taking more automatically produces more energy. Coffee Can Reduce Sleepiness, but It Cannot Replace Sleep Caffeine can temporarily increase alertness and reduce the perception of sleepiness. It cannot make up for insufficient or poor-quality sleep. When i...

Η σκιά της ομπρέλας μειώνει την άμεση έκθεση στον ήλιο, δεν δημιουργεί όμως μια ζώνη χωρίς υπεριώδη ακτινοβολία. Ένα άτομο μπορεί να περάσει αρκετές ώρες κάτω από την ομπρέλα και να διαπιστώσει αργότερα ότι το δέρμα έχει κοκκινίσει και πονά. Αυτό συμβαίνει επειδή η υπεριώδης ακτινοβολία δεν φτάνει στο σώμα μόνο σε ευθεία γραμμή από τον ήλιο. Μέρος της ακτινοβολίας διαχέεται στην ατμόσφαιρα και φτάνει στη σκιά από διαφορετικές κατευθύνσεις. Παράλληλα, η άμμος, το νερό και άλλες φωτεινές επιφάνειες ανακλούν ένα μέρος της ακτινοβολίας. Η προστασία που προσφέρει η ομπρέλα εξαρτάται επίσης από το μέγεθος, το ύφασμα, τη θέση του ήλιου και το αν ολόκληρο το σώμα παραμένει πραγματικά στη σκιά. Η UVA και η UVB δεν συμπεριφέρονται με τον ίδιο τρόπο Η UVB συνδέεται στενά με το ηλιακό έγκαυμα και συμβάλλει στην ανάπτυξη καρκίνου του δέρματος. Η UVA διεισδύει βαθύτερα, συμβάλλει στη φωτογήρανση και επίσης αυξάνει τον καρκινικό κίνδυνο. Και οι δύο μπορούν να βλάψουν το δέρμα, γι' αυτό το αντ...

The shade of a beach umbrella reduces direct sunlight, but it does not create a zone free from ultraviolet radiation. A person can spend several hours under an umbrella and later discover that the skin is red and painful because UV radiation does not reach the body only in a straight line from the sun. Some radiation is scattered in the atmosphere and reaches shaded areas from different directions. Sand, water and other bright surfaces also reflect part of the radiation. The protection provided by an umbrella depends on its size, fabric, the position of the sun and whether the whole body remains in the shade. UVA and UVB behave differently UVB is strongly associated with sunburn and contributes to skin cancer. UVA penetrates more deeply, contributes to premature skin ageing and also increases cancer risk. Both can damage the skin, which is why sunscreen should provide broad-spectrum protection. Not feeling intense heat does not mean that UV exposure is low. Ultraviolet radiation ca...

Contact lenses make daily life easier, but in the sea or a swimming pool they can become a risk factor for eye disease. Tap water, pool water, lakes and seawater are not sterile. They may contain bacteria, fungi and other microorganisms that do not usually harm an intact eye but can become trapped between a lens and the cornea. Water may also cause a lens to change shape or adhere more tightly to the eye. Microscopic damage to the cornea and prolonged contact with microorganisms increase the risk of keratitis, an inflammation or infection that requires timely treatment. Clear water is not sterile water Chlorination reduces many microorganisms but does not make pool water sterile. Seawater may contain microbes, organic material and particles that irritate the eye. Even when tap water is safe to drink, it is not sterile and should never be used to rinse or store contact lenses. Only the contact-lens solution recommended by an eye-care professional should be used for cleaning and stor...

Hot weather affects more than comfort for a person with diabetes. It can alter fluid needs, insulin absorption, physical activity and the interpretation of symptoms such as sweating, weakness and dizziness. High temperatures can also damage insulin, test strips and some electronic devices. People do not all respond in the same way. Dehydration may raise glucose, while vasodilation, faster insulin absorption or increased activity may contribute to hypoglycaemia. More frequent monitoring and an individual plan are therefore safer than arbitrary treatment changes. Why dehydration can raise blood glucose When the amount of water in the body falls, glucose in the bloodstream may become more concentrated. High glucose can then increase urination and worsen fluid loss, creating a cycle of dehydration and hyperglycaemia. Thirst is not always an early warning sign, particularly in older adults. Regular water intake, unless a clinician has prescribed fluid restriction because of heart or kid...

A dish on the table, a sandwich in a beach bag or leftovers from a summer meal may seem safe because they look and smell normal. However, bacteria that cause foodborne illness do not always change the smell, taste or appearance of food. Time and temperature are critical. Microorganisms multiply more rapidly in warm conditions, particularly in moist, protein-rich foods. Safety limits therefore become stricter when food is served outdoors, carried in a car or taken to the beach. The two-hour rule and the one-hour exception Perishable food should not remain at room temperature for more than two hours. When the temperature is above approximately 32°C or 90°F, the safe limit falls to one hour. The clock begins when food leaves refrigeration or is no longer being held hot. Direct sunlight or a closed vehicle can produce temperatures far higher than the weather forecast. A sandwich left in a hot car for two hours is not safe simply because the bread looks dry. Foods that require particu...

How unsupervised testosterone use can affect fertility—and what a new, still preliminary analysis suggests about male hormone levels over the past 50 years. Key point: The widely reported 54% decline comes from an analysis presented at a scientific conference. It has not yet been published as a complete, peer-reviewed paper. The result deserves attention, but it is not definitive proof. Testosterone has become one of social media’s latest obsessions. Fitness influencers, podcasters and content creators increasingly present testosterone replacement therapy, or TRT, as a shortcut to greater strength, energy, confidence, muscle growth and sexual performance. In some videos, young men display testosterone injections or gels as casually as they might show a daily supplement. The message is simple and persuasive: if you feel tired, unmotivated or dissatisfied with your performance, low testosterone is probably the reason. The medical reality is far more complex. Exogenous testosterone is...

A jellyfish sting can cause anything from a limited burning sensation to severe pain, linear skin marks and, more rarely, a serious systemic reaction. Jellyfish tentacles contain microscopic stinging cells called nematocysts, which release venom when activated. Some may remain on the skin after a person leaves the water and continue to discharge if the area is rubbed or treated incorrectly. First aid is not identical for every jellyfish species. This is why advice such as “apply vinegar” may be appropriate for one species and harmful for another. In the Mediterranean, where Pelagia noctiluca is common, vinegar is not a universal treatment and may trigger further nematocyst discharge. Leave the water safely The first step is to get out of the water, particularly if pain is severe or the person feels dizzy. Do not rub the area with hands, a towel or sand. Rubbing can trigger stinging cells that have not yet released their venom. The area can initially be rinsed gently with seawater. ...

A beer on the beach or a drink before an evening swim may seem harmless, particularly to someone who swims well and knows the area. Alcohol, however, affects the abilities needed for safe swimming: judgement, balance, coordination, reaction time and accurate risk assessment. The sea is not a controlled environment. Currents, waves, sudden changes in depth, rocks and boat traffic can turn a small error into an emergency. Heat and dehydration add further strain even when the amount of alcohol does not seem large. Alcohol affects more than “clear thinking” After drinking, the ability to judge distance, effort and personal limits becomes less reliable. A person may swim farther, ignore fatigue or underestimate a current. Reduced balance also increases the risk of falling from rocks, a pier or a boat. Reaction time slows and coordination becomes less precise. These changes matter even before someone feels drunk. Strong swimmers are not protected Swimming experience reduces some risk...

A red rash after a day in hot weather is often blamed generally on “the sun.” However, sunburn, heat rash and polymorphic light eruption, commonly described as sun allergy, have different mechanisms, features and approaches to treatment. Appearance, body location, whether pain or itching dominates and the time since exposure can provide useful clues. They cannot replace medical diagnosis, particularly when a rash is extensive, painful or accompanied by systemic symptoms. Sunburn: painful, hot, exposed skin Sunburn is direct damage caused by excessive ultraviolet radiation. The skin becomes warm, tender and painful, while redness may develop gradually over several hours. More severe burns can cause swelling and blisters. It mainly affects exposed skin and does not typically present as clusters of tiny spots in body folds. Peeling develops during the following days as damaged skin cells are shed. Heat rash: when sweat becomes trapped Heat rash, or miliaria, develops when sweat du...

The warning “do not stay in a wet swimsuit or you will get a urinary tract infection” returns every summer. The reality is more complex. Wet fabric does not create a urinary infection by itself and is not the main cause of a vaginal yeast infection. Prolonged moisture, friction, heat and tight clothing can irritate the skin and create conditions that encourage discomfort or microbial overgrowth. The important point is to distinguish three different problems: a urinary tract infection, vulvovaginal candidiasis and simple local irritation. What actually causes a UTI Most UTIs develop when bacteria, often originating from the bowel, enter the urethra and reach the bladder. Women are more susceptible because the urethra is shorter and anatomically closer to the anus. Sexual activity, previous UTIs, certain forms of contraception, menopause, incomplete bladder emptying, urinary catheters and urinary obstruction are recognised risk factors. Inadequate fluid intake and regularly delaying ...

A ferry journey may begin comfortably and, within a short time, turn into nausea, cold sweats, dizziness and an urgent need for fresh air. Motion sickness does not usually mean that something is wrong with the stomach. It develops mainly because the brain receives conflicting information about movement and the body's position. Inside a cabin, the eyes may see a relatively stable room while the vestibular system of the inner ear detects repeated acceleration and rocking. This sensory mismatch can activate neural pathways involved in nausea and vomiting. What happens in the inner ear The vestibular system helps the brain detect direction, acceleration and the position of the head in relation to gravity. It works with vision and signals from muscles and joints to create a coherent sense of balance. When these signals do not agree, some people develop symptoms quickly. Susceptibility varies and can be influenced by age, the intensity of movement, fatigue, anxiety and previous exper...

Wildfire smoke is not dangerous only near the flames. It can travel long distances, reduce air quality in cities and islands and affect people who cannot see the fire itself. The main concern is a complex mixture of gases and particles, especially very small PM2.5 particles that can travel deep into the lungs. The smell of smoke is a warning but not a reliable measure of risk. Particle concentrations may remain high even when the smell appears weaker. Official air-quality information and civil-protection instructions take priority. What smoke inhalation can cause In the short term, smoke may cause stinging eyes, throat irritation, coughing, wheezing, headache, breathlessness and chest tightness. It can worsen asthma, chronic obstructive pulmonary disease and cardiovascular disease. Fine particles are not stopped completely by the nose and throat. They penetrate deeper into the respiratory system and can trigger inflammation. Effects depend on concentration, duration, physical exert...

Sleep and gut health are often presented as two separate aspects of wellbeing. One concerns rest, energy and brain function, while the other is associated with digestion, immunity and nutrition. Research, however, suggests that the two systems interact through circadian rhythms, metabolic processes, immune signalling and the microbiome–gut–brain axis. This does not mean that poor sleep is caused by an “unhealthy gut” or that taking a probiotic can cure insomnia. Most of the available research identifies associations rather than clear cause-and-effect relationships, while many of the proposed biological mechanisms have been studied more extensively in animals than in humans. Understanding what the evidence actually shows can help distinguish promising scientific findings from exaggerated wellness claims. What do we mean by gut health? Gut health does not have a single, universally accepted medical definition. It generally refers to the ability of the gastrointestinal system to diges...

A sudden muscle cramp can be intensely painful. The muscle tightens involuntarily, feels hard to the touch and may remain sore even after the contraction has subsided. When this happens, the first explanation many people hear is that they must be deficient in magnesium. The usual recommendation follows almost automatically: take a supplement, eat a banana or drink an electrolyte beverage. Magnesium is essential for normal nerve and muscle function, and a severe deficiency can indeed cause muscle cramps. However, the presence of a cramp does not prove that a magnesium deficiency exists. Cramps may result from muscle fatigue, excessive exertion, heat exposure, fluid and sodium loss, medication use, circulatory or neurological problems and several other medical conditions. The evidence also does not support the routine use of magnesium supplements for every type of cramp. A Cochrane systematic review found that magnesium was unlikely to provide a clinically meaningful benefit for common i...