Dear Doctor: I'm 75 years old and have bruising on my hands, seemingly when anything touches them. I do not take blood thinners or aspirin. Occasionally I take an Aleve, which seems to make it worse.

Dear Reader: Such bruising is an annoying, yet common, problem as our bodies age. Many of my patients are flummoxed by the bruises on their skin, not even recalling any trauma that led to the purplish marks. Easy bruising as we age can be traced to several factors.

First, the distribution of fat changes. This is one of the crueler aspects of aging. Older bodies store more fat in the belly and lose the fat under the skin. This is most easily seen in the face, arms and in the back of the hands. Skin that has lost its subcutaneous fat has lost much of its cushion to absorb trauma. Without this cushion, the small blood vessels that course within and below the skin are more susceptible to direct trauma, leading to bleeding underneath the skin.

Second, the skin loses collagen, its most common protein. After the age of 20, a person produces 1 percent less collagen in the skin each year. So by the age of 75, the collagen loss is substantial. This causes the skin to become thinner and more fragile. Without this protection, the blood vessels underneath the skin are more prone to damage.

Third, the skin is less elastic. This means that the skin loses its ability to stretch and absorb external forces.

Finally, the small blood vessels within the layers of skin lose their elasticity as well. This increased fragility allows them to break with only minimal force.

To minimize the impact of these skin changes, you should be aware that the loss of elasticity and collagen are made worse by prolonged sun exposure. Using sunscreen on your arms and the backs of your hands will help to preserve the collagen and elastin within the skin. In addition, topical vitamins, such as vitamins A, E, C and B3 may also help to prevent sun damage. Lastly, smoking cigarettes also degrades collagen and elastin, so I would recommend not smoking.

You mentioned that you are not taking any blood thinners, but you are. Aleve (Naproxen) is a non-steroidal anti-inflammatory and, like all NSAIDS, thins the blood by reducing the ability of platelets to attach to one another. So that is why your symptoms are worse with Aleve. Supplements such as oral vitamin E or fish oil may also thin the blood, making you more susceptible to bruising.

If your bruising is accompanied by a reduced ability of your blood to clot -- which you would notice if you were to get a small cut -- you should consult a physician. This can occur because of blood thinners, but it can also be caused by a blood disorder.

In your case, I would recommend sun protection to the backs of your hands to decrease sun damage to the skin. Also, you should consider stopping Aleve and switching to Tylenol for pain relief; it doesn't have the same blood-thinning effect.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Readers: We've been reading your letters. Thank you for your interest in our thoughts, the humor with which you evaluate -- and sometimes chide -- us, and the passion you continue to show for health sciences and research. Your thoughts and questions are always interesting, often touching and never fail to make us think.

With that in mind, we're following up on some past columns that caused a stir with readers.

Toenail fungus: The column about toenail fungus remains a hot topic. As you may recall, this is a common infection that causes nails to thicken, darken and become malformed. The most effective treatment is an oral anti-fungal drug, such as Lamisil or Sporanox, which can come with side effects. Prescription topical treatments like the medicated nail polish Penlac or antifungal creams are also available. But whichever route you go, this can be a tough infection to beat.

Quite a few of you have offered two interesting home remedies, each of which has been the subject of several studies. Unfortunately, neither of these will actually cure the fungus. But the research agrees with you readers that the appearance of the affected nails can be improved, and the extent of the fungal damage lessened.

-- Topical treatment with tea tree oil: A natural (and quite strong-smelling) disinfectant, this essential oil is derived from the native Australian plant Melaleuca alternifolia. Readers recommend that you apply it to infected nails twice daily for at least eight weeks. For the fungus to be eradicated, the nail must grow out completely. That means results can take up to a year. Tea tree oil is widely available at health food stores and sometimes in the nutritional supplements section of your local drug store.

-- Topical treatment with Vicks VapoRub: The combination of camphor, eucalyptus oil and menthol, the three main ingredients in Vicks VapoRub, is believed to stop the growth of certain fungi. Follow the same application process as for tea tree oil. Numerous readers swear by this.

And for a bit of preventive hygiene, use rubbing alcohol on nail clippers between uses to prevent the risk of further infection.

Nosebleeds: In response to the column explaining the hows and whys of sudden nosebleeds, a reader shared a tip for individuals whose homes are heated with forced air, or who live in arid environments. She followed her physician's advice to put a dab of K-Y Jelly into each nostril at bedtime (not Vaseline, which is petroleum-based), and the nosebleeds that had plagued her stopped.

Copper pans: A reader considering the purchase of a set of unlined copper pans wondered if they pose a health risk. The answer is: It depends on what they're used for.

Copper is easily dissolved by acidic foods like tomatoes or tomato sauce, which should never be cooked or stored in copper. While small amounts of copper are considered safe, when ingested in large amounts it can cause nausea, vomiting and diarrhea.

If you do use unlined copper pots and pans, research the acidity of the foods you plan to cook in them. Or buy a couple of pretty ones and use them for decor.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: What are the benefits and risks of taking kava?

Dear Reader: The kava shrub originates from the South Pacific, where Pacific Islanders used it to promote psychological and physical relaxation for medicinal and ceremonial purposes. Within traditional cultures, the root of the plant is crushed, ground and then combined with a mixture of water and coconut milk to make it drinkable. In the naturopathic boom of the 1990s, kava was touted as a safe alternative to other medications used for anxiety. Today, kava is a popular supplement for anxiety, and various brands can be found in any health food store.

The root of the kava plant contains 18 different phytochemicals, or plant-based compounds, known as kavalactones. These compounds alter the conduction of nerve signals, decrease excitatory neurotransmitters, increase the ability of the amino acid GABA to bind its receptors, inhibit the enzyme monoamine oxidase, and reduce uptake of the neurotransmitters noradrenaline and dopamine. All of this is a technical way of saying: Kava can help reduce anxiety.

A 2003 review of 11 randomized controlled trials with a total of 645 patients assessed kava supplements' ability to treat anxiety. The studies used varying levels of the kavalactones, from 60 to 280 milligrams. These doses are significantly higher than what Pacific Islanders traditionally used. The studies varied from one to 25 weeks.

Ten of the 11 studies showed a decrease in anxiety compared with placebo. These benefits appeared to be comparable to the effect of tranquilizers such as benzodiazepines and the anxiety drug buspirone. Side effects included nausea, stomach aches, drowsiness and headaches. No liver toxicity was reported, but then, no liver tests were performed.

Note that kava has been banned in the United Kingdom and within Europe due to liver toxicity. More than 100 cases of liver toxicity related to the use of kava have been identified, some leading to liver transplant and others leading to death. There are many reasons for liver damage. For one, kava depletes glutathione, a chief antioxidant, within the liver. It also inhibits enzymes involved in the metabolism of many drugs. Many of the cases of liver toxicity were seen in people who had prior liver disease or used alcohol in addition to kava.

You may think kava is safe if you don't have liver disease or are not taking medications metabolized by the liver, but that might not be the case. A study of 31 people in Hawaii who were regular kava drinkers showed a significantly greater elevation of two liver enzymes compared with people who were not kava drinkers. There is some evidence that kava that is prepared with water is less harmful to the liver than suspensions prepared in acetone or ethanol.

Studies have shown that consumption of kava supplements leads to a slower reaction time and an impairment of motor skills. However, there has been no proof of any decline in cognitive function. Also, because it inhibits multiple enzymes and has psychoactive properties, kava likely should not be taken with anti-depressants.

In summary, kava may help relieve anxiety in the short term. However, due to the severe side effects at its current doses, I would be hesitant to use it for the short term and recommend not using it in the long-term. Cognitive behavioral therapy has greater long-lasting benefits.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)