Dear Dr. Garner, 
My wife and I recently went on a trip to Hawaii.
Unfortunately, after the long flight there, I spent my vacation in the hospital with something known as deep vein thrombosis.
What is this and how I can ensure this doesn’t happen again?
Worried in Williamsburg

Dear Worried,
For those who don’t know what deep vein thrombosis is, it is merely a term for blood clots that develop in the veins. In your case, they developed in the veins of the legs.
The symptoms, which I’m sure you experienced, include leg pain, swelling of the affected leg, increased warmth of the leg, and  a red color of the skin of the leg.  This can be a very serious condition as the clots from the legs can break loose and travel to the lungs, causing a pulmonary clot or embolus, which can lead to death. It therefore becomes essential that the proper diagnosis and treatment occurs as quickly as possible.
The condition was originally known as “coach-class syndrome,” because it was felt that the cramped conditions in coach, with the bending of the legs, caused an increased likelihood of developing clots. We now know that this condition does not spare the first-class passenger either.
Flying conditions, including prolonged sitting and pressure changes, predispose people to developing clots. In addition, because of the air flow system in the plane, most people become dry and dehydrated. Alcohol consumption contributes to the dehydration. All of these factors put passengers at increased risk.
You can take simple steps to prevent this condition when you fly:
1. Stay well hydrated and avoid alcohol.
2. Never cross your legs on the plane.
3. Get up to walk at least every 30 minutes. From your seat, you can exercise by pointing your toes up and down every 30 minutes. You should feel your calf muscles contracting.
4.  Some people suggest taking an aspirin before you fly. If it is a long flight, and you don’t have a history of ulcers, I would recommend this.
Certain conditions cause people to be more likely to develop clots. These include: estrogen use; pregnancy; recent surgery; leg trauma, particularly a fracture; cancer; and a history of previous blood clots.
The diagnosis of blood clots can be done in about a minute. with a Doppler ultrasound test.
It is important to have the test done at a facility with a licensed and credentialed staff that can institute treatment if warranted.
The main treatment is a blood thinner known as heparin, which helps to prevent the likelihood that a clot from the legs will travel to the lungs. This treatment must be started as soon as possible to be effective, and to  prevent permanent damage to the veins.
If you follow the tips above, you should not have this problem again.

Dear Dr. Garner,
In recent years, some of the veins on my legs have become very visible, so much so that I’m too embarrassed to wear shorts. Do you have any suggestions?
Spider Vein Embarrassment in Sunnyside

Dear Spider Veins,
For those who don’t know what spider veins are, they are tiny blood vessels that may appear on the face, legs and ankles.  They are bluish, purple or red and often form web-like netting just below the skin’s surface. They’re more of an unattractive nuisance than an actual health problem.
Spider veins are not to be confused with varicose veins, or veins near the surface of the skin on the legs, which have become permanently distended and filled with blood. The veins have valves that usually prevent blood from flowing backwards due to gravity. When a valve malfunctions or vein wall weakens, blood collects in the vein, forcing it to bulge.
Varicose veins are bluish or purple in color and can protrude from the leg. They may cause discomfort such as swelling, throbbing, heaviness, night cramps and long-term complications, such as ulcerations or bleeding.
The main cause of both spider veins and varicose veins is heredity.  The risk of developing these leg vein problems increases for women who are pregnant. Obesity and lack of exercise, which weakens the system of leg veins, are also factors.
Once spider and varicose veins develop, there is no way for the body to cure them.
However, you can prevent varicose and spider veins from spreading by:
• Wearing sunscreen to limit spider veins on the face.
• Exercising regularly to boost leg strength and circulation.
• Controlling your weight.
• Keeping your legs uncrossed while sitting.
• Not standing or sitting for long periods of time.
• Wearing elastic support stockings and avoiding tight clothing.
• Eating a low-salt diet, rich in high-fiber food.
Sclerotherapy, otherwise known as “injection therapy,” and/or laser treatments can be used to treat spider veins in the legs. They are effective and have a high success rate. However, more abnormal veins can develop as there is no cure for weak vein valves.

Dr. Steven Garner is a Fidelis Care provider who is affiliated with New York Methodist Hospital, Park Slope. He also hosts “Ask the Doctor” on The NET, Tuesdays at 8 p.m. on Channel 97 Time Warner and Channel 30 Cablevision.