Varicose Veins - Causes, Prevention, and the Mechanism Behind Bulging Leg Veins

Varicose Veins Affect Roughly 40% of Adults

Varicose veins are leg veins that have dilated and twisted until they bulge visibly beneath the skin. In Japan, where this site is based, some form of varicose veins is found in roughly 40% of adults, in line with prevalence reported across industrialized countries, and the rate climbs with age. The condition is not life-threatening, but beyond the cosmetic concern it can cause heavy, tired legs, swelling, night cramps, and brown discoloration of the skin, and in advanced cases it can progress to skin ulcers.

Varicose veins are easy to dismiss as "just cosmetic," but they are a circulatory disorder, chronic venous insufficiency, and they deserve proper prevention and management.

The Root Cause: Failing Valves Inside the Veins

Arteries carry blood outward on the heart's pumping power; veins have the harder job of returning it. The veins of the legs must push blood upward against gravity, and they manage it with two mechanisms: one-way valves inside the veins that block backflow, and the calf muscle pump that squeezes blood upward with every step.

When a venous valve fails, blood flows backward and pools in the leg veins (venous stasis). The pressure of the pooled blood stretches the vein wall, which causes more valves to fail, and the cycle feeds itself. The end state, a vein so dilated and tortuous that it stands out under the skin, is a varicose vein.

Risk Factors: Who Gets Them?

Heredity

If either parent has varicose veins, a child's risk roughly doubles. The collagen structure of vein walls and the strength of the valves vary genetically.

Jobs spent standing or sitting

Work spent on your feet all day (retail staff, hairdressers, cooks, teachers) lets gravity pool blood in the leg veins. All-day desk work is risky for the opposite reason: a calf muscle pump that never fires cannot move blood at all.

Pregnancy

During pregnancy, blood volume rises by about 50% while the uterus compresses the pelvic veins, and progesterone relaxes vein walls on top of that. Risk climbs with each pregnancy; varicose veins are found in about 30% of women who have given birth.

Obesity

Obesity at BMI 30 or above roughly triples varicose vein risk, because elevated intra-abdominal pressure obstructs venous return from the legs.

Age

The elastin and collagen in vein walls degrade with age and valve function declines with them; past the 60s, prevalence exceeds 50%.

Types of Varicose Veins and a Self-Check

Saphenous varicose veins

These arise from valve failure in the great saphenous vein (the large superficial vein running up the inner leg) or the small saphenous vein (behind the calf). They form knotted, bulging channels 3 mm or more in diameter, and this is the type most often treated.

Reticular veins

Blue-purple vessels 1 to 3 mm across, visible as a net-like pattern under the skin. These are dilated veins in the shallow skin layers, and the concern is mostly cosmetic.

Spider veins

Fine red-purple vessels under 1 mm across, spreading in a radial or branching pattern. This is the mildest form and rarely causes symptoms.

Self-check

Leg swelling that worsens by evening and clears by morning. Calves that feel heavy and dull. Frequent night cramps. Brown pigmentation on the skin of the lower leg. If several of these apply, suspect varicose veins. Since swelling has many causes, understanding the causes and remedies for leg swelling first, then checking specifically for varicose veins, is the sensible order.

Compression Stockings: Choosing and Using Them Correctly

Compression stockings support venous return by applying graduated pressure, strongest at the ankle and easing upward. They are the conservative therapy with the best evidence for preventing varicose veins and slowing their progression.

Choosing the pressure

For prevention, choose 15-20 mmHg (light compression); for mild varicose veins, 20-30 mmHg (medium); for moderate or worse, 30-40 mmHg (firm). Medical-grade compression stockings are available by physician prescription, and in Japan they are sometimes covered by health insurance; coverage rules differ by country, so check yours. Retail compression socks run lighter but are adequate for prevention.

Putting them on correctly

Put them on in the morning, before the legs swell. Turn the stocking inside out to the heel, work it on from the toes, and smooth it up evenly so no wrinkles form. Take them off for sleep; lying down removes gravity from the equation, so they are unnecessary overnight.

Prevention Through Exercise and Daily Habits

Activate the calf muscle pump

Aerobic exercise that works the calves is the core preventive: walking, jogging, swimming, cycling. Aim for 30 minutes a day, five or more days a week. During desk work, do calf raises in your chair, alternating onto tiptoes and back onto heels, 20 repetitions every hour. Over the years, building an exercise habit forms the foundation of varicose vein prevention.

Elevate your legs to rest

At the end of the day, rest for 15 to 20 minutes with your legs above heart level. Propping the feet 15 to 20 cm up on cushions or pillows is enough. Venous return improves and swelling recedes.

Manage your weight and posture

Keeping a healthy weight directly lowers varicose vein risk: target a BMI under 25, and reduce abdominal fat in particular to bring intra-abdominal pressure down. Everyday posture improvement also aids venous return; slouching and a posteriorly tilted pelvis raise abdominal pressure and impede blood flow from the legs.

Prevention Strategy by Age

20s and 30s

If varicose veins run in your family, start prevention early. In standing or sitting jobs, build the habit of walking every hour. If you are planning a pregnancy, consider starting compression stockings before it begins.

40s and 50s

This is when varicose veins typically become visible. Begin daily compression stocking use and make calf strengthening routine. If skin pigmentation or itching appears, see a vascular surgeon.

60s and beyond

Skin ulcer risk rises in these decades, so moisturize and protect the skin of the lower legs diligently. If varicose veins are already established, consult a vascular surgeon about laser treatment or stripping surgery. Minimally invasive day procedures have become widespread and the barrier to treatment is far lower than it once was. Endovenous laser ablation (EVLA) is performed under local anesthesia: a catheter is threaded into the vein and laser energy seals the vessel closed. Compression stockings are worn for one to two weeks afterward, and normal life resumes the next day.

When to See a Doctor

See a vascular or cardiovascular surgeon if leg veins are visibly bulging, swelling has become chronic, the skin shows pigmentation or itching, or cramps strike frequently. A painless ultrasound scan can confirm valve backflow and settle the diagnosis. Varicose veins do not heal on their own, but with proper prevention and treatment, their progression can be stopped.