How Do Allergies Affect COPD?
Meter That's A Breath Of Fresh Air For Lovers
Ben Taylor
It is the ultimate accessory for the smooth-talking Romeo who fears he
has everything a woman desires ? Except sweet breath.
No more will he have to puff into the palm of his hand in an attempt to
smell it himself. A pocket-sized 'halimeter' is being developed to gauge the
level of odour in the mouth and thus warn him to do something about his
halitosis.
The monitor is being developed by Spanish chemist Alfredo Sanz-Medel in
his laboratory at the University of Oviedo.
It measures the
amount of volatile sulphur compounds in the mouth.
These are the gases released when food is broken down by bacteria in the
mouth.
Mr Sanz-Medel explained: 'We are in the preliminary steps but I am sure we
could shrink the device to handheld size.'
Until now, those who suffer from
bad breath have had little help in determining whether they have a problem.
A common, albeit unpleasant, trick has been to lick the back of the wrist,
leave the saliva for ten seconds then smell it.
Sufferers with money to burn can, however, opt for a consultation with a
specialist who will use his or her highly-trained nose to sniff out any
unwelcome odours.
There is even a self-help group for like-minded patients.
'The problem is one of habituation,' said Dr Philip Stemmer of the
London-based Fresh Breath Centre.
'People often cannot tell if they have bad breath themselves because they
become used to the smell.
'For example, if you walk into a burger bar, for the first three of four
minutes you will smell frying onions.
'But after ten minutes, the smell will pass because you have become used
to it ? Even though it hasn't actually gone away.'
Bacteria is usually formed
on excess food which has not been removed in brushing the teeth. It is mainly
trapped in the gums or in gaps between the teeth.
Contrary to what many believe, bad breath does not originate from the
stomach but from the mouth. It is often worse after a night's sleep - causing
so-called 'morning breath'.
Alcohol, too, can be a factor because it dries the palate, leaving it more
vulnerable to lurking gases. Dr Stemmer, who treats hundreds of patients a
year at his London clinic, sounded a word of caution.
'Halitosis has become a big problem for a number of people,' he said. 'It
is said that 65 per cent of people have suffered at some time. 'A pocket-sized device to measure it would be a great step forward.
But it would have to be very accurate or it would lull you into a false
sense of security.'
{"status":"error","code":"499","payload":"Asset id not found: readcomments comments with assetId=729, assetTypeId=1"}High Altitude: Acclimatization And Illnesses
Friday March 29, 2024
by Rick Curtis, Director, Outdoor Action ProgramTraveling at high altitude can be hazardous. The information provided here is designed for educational use only and is not a substitute for specific training or experience. Princeton University and the author assume no liability for any individual's use of or reliance upon any material contained or referenced herein. This paper is prepared to provide basic information about altitude illnesses for the lay person. Medical research on high altitude illnesses is always expanding our knowledge of the causes and treatment. When going to altitude it is your responsibility to learn the latest information. The material contained in this article may not be the most current.
High altitude-we all enjoy that tremendous view from a high summit, but there are risks in going to high altitude, and it's important to understand these risks. Here is a classic scenario for developing a high altitude illness. You fly from New York City to a Denver at 5,000 feet (1,525 meters). That afternoon you rent a car and drive up to the trailhead at 8,000 feet (2,438 meters). You hike up to your first camp at 9,000 feet (2,745 meters). The next day you hike up to 10,500 feet (3,048 meters). You begin to have a severe headache and feel nauseous and weak. If your condition worsens, you may begin to have difficulty hiking. Scenarios like this are not uncommon, so it's essential that you understand the physiological effects of high altitude.
What is High Altitude?Altitude is defined on the following scale High (8,000 - 12,000 feet [2,438 - 3,658 meters]), Very High (12,000 - 18,000 feet [3,658 - 5,487 meters]), and Extremely High (18,000+ feet [5,500+ meters]). Since few people have been to such altitudes, it is hard to know who may be affected. There are no specific factors such as age, sex, or physical condition that correlate with susceptibility to altitude sickness. Some people get it and some people don't, and some people are more susceptible than others. Most people can go up to 8,000 feet (2,438 meters) with minimal effect. If you haven't been to high altitude before, it's important to be cautious. If you have been at that altitude before with no problem, you can probably return to that altitude without problems as long as you are properly acclimatized.
What Causes Altitude IllnessesThe concentration of oxygen at sea level is about 21% and the barometric pressure averages 760 mmHg. As altitude increases, the concentration remains the same but the number of oxygen molecules per breath is reduced. At 12,000 feet (3,658 meters) the barometric pressure is only 483 mmHg, so there are roughly 40% fewer oxygen molecules per breath. In order to properly oxygenate the body, your breathing rate (even while at rest) has to increase. This extra ventilation increases the oxygen content in the blood, but not to sea level concentrations. Since the amount of oxygen required for activity is the same, the body must adjust to having less oxygen. In addition, for reasons not entirely understood, high altitude and lower air pressure causes fluid to leak from the capillaries which can cause fluid build-up in both the lungs and the brain. Continuing to higher altitudes without proper acclimatization can lead to potentially serious, even life-threatening illnesses.
AcclimatizationThe major cause of altitude illnesses is going too high too fast. Given time, your body can adapt to the decrease in oxygen molecules at a specific altitude. This process is known as acclimatization and generally takes 1-3 days at that altitude. For example, if you hike to 10,000 feet (3,048 meters), and spend several days at that altitude, your body acclimatizes to 10,000 feet (3,048 meters). If you climb to 12,000 feet (3,658 meters), your body has to acclimatize once again. A number of changes take place in the body to allow it to operate with decreased oxygen.
Prevention of altitude illnesses falls into two categories, proper acclimatization and preventive medications. Below are a few basic guidelines for proper acclimatization.
AMS is common at high altitudes. At elevations over 10,000 feet (3,048 meters), 75% of people will have mild symptoms. The occurrence of AMS is dependent upon the elevation, the rate of ascent, and individual susceptibility. Many people will experience mild AMS during the acclimatization process. Symptoms usually start 12-24 hours after arrival at altitude and begin to decrease in severity about the third day. The symptoms of Mild AMS are headache, dizziness, fatigue, shortness of breath, loss of appetite, nausea, disturbed sleep, and a general feeling of malaise. Symptoms tend to be worse at night and when respiratory drive is decreased. Mild AMS does not interfere with normal activity and symptoms generally subside within 2-4 days as the body acclimatizes. As long as symptoms are mild, and only a nuisance, ascent can continue at a moderate rate. When hiking, it is essential that you communicate any symptoms of illness immediately to others on your trip. AMS is considered to be a neurological problem caused by changes in the central nervous system. It is basically a mild form of High Altitude Cerebral Edema (see below).
Basic Treatment of AMSThe only cure is either acclimatization or descent. Symptoms of Mild AMS can be treated with pain medications for headache and Diamox. Both help to reduce the severity of the symptoms, but remember, reducing the symptoms is not curing the problem. Diamox allows you to breathe faster so that you metabolize more oxygen, thereby minimizing the symptoms caused by poor oxygenation. This is especially helpful at night when respiratory drive is decreased. Since it takes a while for Diamox to have an effect, it is advisable to start taking it 24 hours before you go to altitude and continue for at least five days at higher altitude. The recommendation of the Himalayan Rescue Association Medical Clinic is 125 mg. Twice a day (morning and night). (The standard dose was 250 mg., but their research showed no difference for most people with the lower dose, although some individuals may need 250 mg.) Possible side effects include tingling of the lips and finger tips, blurring of vision, and alteration of taste. These side effects may be reduced with the 125 mg. Dose. Side effects subside when the drug is stopped. Contact your physician for a prescription. Since Diamox is a sulfonamide drug, people who are allergic to sulfa drugs should not take Diamox. Diamox has also been known to cause severe allergic reactions to people with no previous history of Diamox or sulfa allergies. Frank Hubbell of SOLO in New Hampshire recommends a trial course of the drug before going to a remote location where a severe allergic reaction could prove difficult to treat.
Moderate AMSModerate AMS includes severe headache that is not relieved by medication, nausea and vomiting, increasing weakness and fatigue, shortness of breath, and decreased coordination (ataxia). Normal activity is difficult, although the person may still be able to walk on their own. At this stage, only advanced medications or descent can reverse the problem. Descending even a few hundred feet (70-100 meters) may help and definite improvement will be seen in descents of 1,000-2,000 feet (305-610 meters). Twenty-four hours at the lower altitude will result in significant improvements. The person should remain at lower altitude until symptoms have subsided (up to 3 days). At this point, the person has become acclimatized to that altitude and can begin ascending again. The best test for moderate AMS is to have the person "walk a straight line" heel to toe. Just like a sobriety test, a person with ataxia will be unable to walk a straight line. This is a clear indication that immediate descent is required. It is important to get the person to descend before the ataxia reaches the point where they cannot walk on their own (which would necessitate a litter evacuation).
Severe AMSSevere AMS presents as an increase in the severity of the aforementioned symptoms, including shortness of breath at rest, inability to walk, decreasing mental status, and fluid buildup in the lungs. Severe AMS requires immediate descent to lower altitudes (2,000 - 4,000 feet [610-1,220 meters]).
There are two other severe forms of altitude illness, High Altitude Cerebral Edema (HACE) and High Altitude Pulmonary Edema (HAPE). Both of these happen less frequently, especially to those who are properly acclimatized. When they do occur, it is usually with people going too high too fast or going very high and staying there. The lack of oxygen results in leakage of fluid through the capillary walls into either the lungs or the brain.
High Altitude Pulmonary Edema (HAPE)HAPE results from fluid buildup in the lungs. The fluid in the lungs prevents effective oxygen exchange. As the condition becomes more severe, the level of oxygen in the bloodstream decreases, and this can lead to cyanosis, impaired cerebral function, and death. Symptoms include shortness of breath even at rest, "tightness in the chest," marked fatigue, a feeling of impending suffocation at night, weakness, and a persistent productive cough bringing up white, watery, or frothy fluid. Confusion, and irrational behavior are signs that insufficient oxygen is reaching the brain. One of the methods for testing yourself for HAPE is to check your recovery time after exertion. If your heart and breathing rates normally slow down in X seconds after exercise, but at altitude your recovery time is much greater, it may mean fluid is building up in the lungs. In cases of HAPE, immediate descent is a necessary life-saving measure (2,000 - 4,000 feet [610-1,220 meters]). Anyone suffering from HAPE must be evacuated to a medical facility for proper follow-up treatment.
High Altitude Cerebral Edema (HACE)HACE is the result of swelling of brain tissue from fluid leakage. Symptoms can include headache, loss of coordination (ataxia), weakness, and decreasing levels of consciousness including, disorientation, loss of memory, hallucinations, psychotic behavior, and coma. It generally occurs after a week or more at high altitude. Severe instances can lead to death if not treated quickly. Immediate descent is a necessary life-saving measure (2,000 - 4,000 feet [610-1,220 meters]). There are some medications that may be prescribed for treatment in the field, but these require that you have proper training in their use. Anyone suffering from HACE must be evacuated to a medical facility for proper follow-up treatment.
Other Medications for Altitude IllnessesThis clever invention has revolutionized field treatment of high altitude illnesses. The bag is basically a sealed chamber with a pump. The person is placed inside the bag and it is inflated. Pumping the bag full of air effectively increases the concentration of oxygen molecules and therefore simulates a descent to lower altitude. In as little as 10 minutes the bag can create an "atmosphere" that corresponds to that at 3,000 - 5,000 feet (915 - 1,525 meters) lower. After a 1-2 hours in the bag, the person's body chemistry will have "reset" to the lower altitude. This lasts for up to 12 hours outside of the bag which should be enough time to walk them down to a lower altitude and allow for further acclimatization. The bag and pump weigh about 14 pounds (6.3 kilos) and are now carried on most major high altitude expeditions. Bags can be rented for short term trips such as treks or expeditions.
Cheyne-Stokes RespirationsAbove 10,000 feet (3,000 meters) most people experience a periodic breathing during sleep known as Cheyne-Stokes Respirations. The pattern begins with a few shallow breaths and increases to deep sighing respirations then falls off rapidly. Respirations may cease entirely for a few seconds and then the shallow breaths begin again. During the period when breathing stops the person often becomes restless and may wake with a sudden feeling of suffocation. This can disturb sleeping patterns, exhausting the climber. Acetazolamide is helpful in relieving the periodic breathing. This type of breathing is not considered abnormal at high altitudes. However, if it occurs first during an illness (other than altitude illnesses) or after an injury (particularly a head injury) it may be a sign of a serious disorder.
Sources:Humans Really Can Have Superpowers—scientists Are Studying Them
Superpowers are real. Okay, maybe humans can't sprout giant claws like the X-Men's Wolverine or shoot energy beams from their eyes like Cyclops—but our bodies and brains hold the potential for many seemingly superhuman feats, scientists say.
Sometimes superpowers arise through genetic mutations, a bit like the origin stories in the comics. The Sherpa people of the Himalaya, for instance, have adapted to high altitude with genes that supercharge their strength and endurance.
But other superpowers can be acquired. Mental athletes, who perform amazing feats of memory, swear that anyone can develop a mind like a steel trap. Even fear itself might be conquered with the right conditioning, as seen in the story of climber Alex Honnold, who has been compared to Spider-Man for scaling sheer rock walls without ropes.
(Want to keep your memory sharp? Here's what science recommends.)
Scientists are just starting to learn what's going on inside the bodies and minds of people with these and other heightened abilities. They're finding that while our genes grant some of us an edge, most of us hold untapped potential.
Here are just a few examples of the superheroes hiding among us.
Super fearless: Alex HonnoldFor most people, just looking at a photo of Alex Honnold dangling from a precipice by only his fingers is enough to make the brain crackle with fear.
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Not Honnold's, though. When scientists scanned the world-famous climber's brain using functional MRI in 2016, they found something surprising. When shown graphic images that typically trigger intense activity in the amygdala, a brain region linked to fear, Honnold's amygdala was utterly silent.
Famed climber Alex Honnold—pictured here at the Ahwahnee Boulders in Yosemite National Park—doesn't seem to feel fear like the rest of us. Scientists have studied Honnold's brain to understand how he's been able to control his fear in the face of extreme danger.
Photograph by Jimmy CHin
(How Alex Honnold made "the ultimate climb"—without a rope.)
Structurally, his brain is perfectly normal, and Honnold has long denied being fearless. It's possible that he has conditioned himself to tamp down certain brain activity by focusing instead on meticulously planning each move, wrote Jane Joseph, the neuroscientist who examined Honnold's brain activity, in Popular Science in 2018.
And that's a superpower that the rest of us can tap into. Psychologists use similar conditioning methods to help people overcome fears, and neuroscience is revealing how fear memories are made, and can be undone.
Super resilience: Sherpas"Humans are still evolving," says Tatum Simonson, who studies the genetics and physiology of high-altitude adaptation at the University of California at San Diego. And the Sherpa people of Nepal are a perfect example of evolving a superpower, she says.
Members of this ethnic group have lived for more than 6,000 years at an average 14,000 feet (4,200 meters) above sea level, where there's about 40 percent less oxygen than at sea level. "There's been a lot of time for natural selection to figure out the best way to deal with low oxygen," Simonson says.
Sherpa porters carry loads back down from Mount Everest's base camp to villages for storage in Gorak Shep, Nepal. Over thousands of years of living at high altitude, the Sherpa people have acquired genetic mutations that allow them to use oxygen more efficiently.
Photograph by Aaron Huey
Normally, as oxygen levels drop, the human body pumps out more oxygen-carrying red blood cells, but this thickens the blood and can lead to altitude sickness or even death. Sherpas, on the other hand, have developed several genetic mutations that allow them to maintain low levels of red blood cells while the mitochondria in their cells use oxygen more efficiently.
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Psychedelics may help treat PTSD—and the VA is intriguedSimonson is studying Tibetans' performance at lower altitudes and finds they maintain their advantage even at sea level, a superpower that she hopes to learn from to help people who have chronic low blood oxygen due to respiratory or cardiovascular disease.
Super swimmers: Bajau 'sea nomads'There's a reason we love superheroes who fly high like Superman or swim deep in the ocean like Aquaman: They can go where the rest of us can't.
For free divers, no scuba gear is required to plumb the watery depths. The Bajau people of the Philippines, Malaysia, and Indonesia are particularly renowned for staying underwater for as long as 13 minutes at depths up to 230 feet (70 meters).
(Here's how to get into free-diving, according to the British champion.)
Like Sherpas, scientists say, the Bajau have evolved a genetic advantage to use oxygen more efficiently. However, since they face a more immediate form of oxygen deprivation, the Bajau have developed a speedier mechanism. Over time, natural selection has favored a larger spleen, which holds oxygenated red blood cells. While diving, their spleens contract and spurt this reserve into the bloodstream.
Super agility: Samurai Isao MachiiIn fiction, mythical beings such as vampires and werewolves are imbued with super-agility, the ability to move with extraordinary balance, coordination, and reflexes. In real life, a combination of genetics and training gives some people superhuman moves.
Take swordsman Isao Machii. Fire a bullet at him, and he can chop it in half in midair with a swing of his sword (see it here). Or check out legendary gunslinger Bob Munden, who was tested as drawing and accurately firing his gun in less than a tenth of a second, faster than the reaction time of the average human brain.
Modern-day samurai Isao Machii doesn't hail from the Edo Period like this Japanese man did, but his super-agility—or the ability to move with extraordinary balance, coordination, and reflexes—has already made him the stuff of legend.
Photograph by Ira Block
(The monarch butterfly's spots may be its superpower.)
Scientists are still working to understand how the central nervous system helps people plan and execute such complex movements unconsciously.
Super memory: Mental athletesImagine memorizing the order of a deck of cards in 20 seconds. Or the names and faces of a couple hundred strangers in a matter of minutes. For some of the mental athletes who compete in the annual USA Memory Championship, such feats are a breeze.
Yet there's nothing special about memory champs except that they've put in the practice, says Anthony Dottino, the founder of the championship event. Dottino and his son Michael run memory training programs, and they say that anyone can improve their memory—at any age.
To prove it, Michael Dottino is working with neuroscientists to study how memory training affects brain activity. Already, research is revealing how memory techniques work, by forming networks in the brain that anchor new memories to old ones. What's more, a study in the journal Neuron found that average people can dramatically improve their memories with just six weeks of training.
Now that's a superpower within reach for all of us.
Erika Engelhaupt is the author of the upcoming National Geographic book Superpowered about real-world superpowers (coming in 2026), as well as Gory Details and Go to Hell.
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