My blood type is O- and, knowing there is always a severe shortage, especially of this blood type, I feel so frustrated that because of my age I cannot donate any blood. Is there no alternative? E.S. Kfar Saba Prof. Eilat Shinar, director of Magen David Adom's Blood Services at Tel Hashomer, answers: According to Health Ministry standards, donors who are healthy and have passed their 65th birthday can give blood if they bring a certificate (ishur) from their family physician that they can donate blood without endangering their health. The certificate must have been written no more than a week to 10 days before. People who want to donate for the first time in their life should be under 60 years old, because complications are more prevalent after that age in first timers. I am a healthy, 30-year-old woman who is something of a shoe fanatic - not quite as bad as Imelda Marcos, but I really love shoes, and I usually buy them according to what's in fashion rather that what is good for feet. Do you have any advice on how to choose fashionable shoes that do not cause orthopedic problems? V.G., Tel Aviv Dr. James Brodsky, an orthopedic foot and ankle surgeon at Baylor University Medical Center at Dallas and president of the American Orthopedic Foot and Ankle Society, answers: According to the latest shoe trends in the US at least, round-toe shoes are making a comeback as well as low heels, flat shoes and wedge heels. These types of shoes are actually better for your feet than previous styles, such as narrow-toe shoes and stiletto heels. But in general, when shopping for shoes, make sure that your toes have plenty of room to wiggle around. If your toes are crammed into the toe of the shoe, as is the case with most narrow-toe shoes, it can lead to foot deformities that may need to be corrected by surgery. Low-heeled shoes, with a wide or open toebox, reduce the pressure on the front of the foot. The height of the heel makes a big difference in the pressure that you put on the ball of your foot, but even low-heeled shoes can cause problems if they do not fit properly. Over time, ill-fitting shoes can contribute to foot deformities. Higher-heeled shoes such as stilettos can cause the foot to slip forward, resulting in discomfort, blisters and possible toe injuries. If you're going to wear high heels, choose shoes with cushioning under the toes and ball of the foot. As for keeping your ankles safe, look for shoes with a stable heel, such as current trends like wedges or wide-stacked heels. Flat or low-heeled shoes are a better option to reduce the pain of neuromas, bunions and hammertoes. It's best if they have a substantial amount of cushioning on the outer sole and the insole. Contrary to popular belief, there is no such thing as a "break-in" period. If the shoe doesn't fit, don't wear it. Don't force your feet to conform to the shape of a shoe. Even though you are fashion conscious, you should know that the most important quality to look for in a woman's shoe is durable construction that will protect your feet and keep them comfortable. Believe it or not, fashionable shoes can be comfortable, too. When you do go shoe shopping, it's best to go near the end of the day, as your feet are usually swollen and therefore larger after standing or sitting on them all day long. Have your feet measured, because your feet grow as you become older so it's wise to know the exact size of your foot. Try on both shoes, as one foot is typically larger than the other. Walk around in the shoes, and don't buy a pair of shoes just based on how they look on your feet. Finally, judge a shoe by how it fits your foot and not by the marked size. Shoe sizes vary among shoe brands and styles. I am a 25-year-old man who goes frequently to the swimming pool. I am a policeman who has to wear boots in the winter. I often suffer from athlete's foot fungus, especially in the winter. What can be done to prevent it? R.S., Jerusalem University of Alabama at Birmingham dermatologist Dr. Sarah M. Boyce comments: Athlete's foot, the dreaded "fungus among us," is a common bane of warm locker rooms at schools and fitness centers. The condition also occurs in cold weather when feet may be swaddled in boots and heavy socks for longer hours. The treatment is straightforward, and over-the-counter or prescription anti-fungals usually are effective. But prevention is better: Keep your feet dry and cool and sprinkle shoes and socks with anti-fungal powder. Change socks regularly. Some socks are made with materials such as wool blends that wick moisture away. If possible, use a hot blow-dryer on your feet after showering, but be careful of burns. Rx For Readers welcomes queries from readers about medical problems. Experts will answer those we find most interesting. Write Rx For Readers, the Jerusalem Post, POB 81, Jerusalem 91000, fax your question to Judy Siegel-Itzkovich at (02) 538-9527, or e-mail it to firstname.lastname@example.org, giving your initials, age and residence.