Compression socks are specially designed to gently squeeze your legs, improving blood flow and reducing discomfort. They’re tighter around the ankle and gradually looser up the leg—a design called graduated compression. This helps prevent swelling, fatigue, and even blood clots by encouraging better circulation.
How Do Compression Socks Work?
When you sit or stand for long periods, gravity causes blood and fluid to collect in your lower legs. This can lead to swelling, aches, and tiredness. Compression socks apply gentle pressure to push blood back toward your heart. That pressure gives your veins a little extra help so your legs feel more energized and less sore at the end of the day.
What Are Compression Levels?
Compression strength is measured in millimeters of mercury (mmHg)—just like blood pressure. The higher the number, the tighter the sock. Different levels of compression are made for different needs. Some people want light daily support, while others need stronger pressure for medical reasons.
Here are the most common levels and what they’re used for:
8–15 mmHg (Mild)
- Light pressure
- Great for daily comfort, mild swelling, or tired legs
- Good for people who are new to compression socks or want to prevent problems early
15–20 mmHg (Moderate)
- Most popular everyday level
- Helps with fatigue, minor swelling, and long hours on your feet or sitting
- Great for travel, pregnancy, and general support
20–30 mmHg (Firm)
- Medical-grade compression
- Recommended for varicose veins, moderate swelling, post-surgery recovery
- Should be used under medical guidance if treating a health condition
30–40 mmHg (Extra-Firm)
- High-level compression for serious medical issues
- Used for severe swelling, lymphedema, or after certain surgeries
- Only wear with a prescription or recommendation from a healthcare provider
Choosing Compression for Different Needs
Athletes
Athletes often wear compression socks to boost circulation during workouts and reduce muscle soreness afterward. Most choose 15–20 mmHg for activity. Some go up to 20–30 mmHg for recovery after intense training. These socks help reduce fatigue and speed up muscle repair without being overly tight.
People with Medical Conditions
If you have varicose veins, chronic swelling, or are recovering from surgery, you may need a 20–30 mmHg sock. This level offers firm support to improve blood flow and manage symptoms. People with more serious conditions may be prescribed 30–40 mmHg, but these should always be used under medical supervision.
Travelers
Long flights or car rides can cause leg swelling and discomfort. A 15–20 mmHg sock is usually enough to reduce swelling and prevent blood clots. It’s also great for people who stand or sit for long hours at work. If you’re at higher risk for circulation issues, a doctor may suggest something stronger.
Finding Your Fit
Here’s a simple guide:
- For everyday comfort or prevention: Start with 15–20 mmHg
- For workouts or recovery: Use 15–20 mmHg during activity, 20–30 mmHg after
- For medical use: Talk to a doctor; 20–30 mmHg is common, 30–40 mmHg only with supervision
- For travel or long hours sitting/standing: Go with 15–20 mmHg
The bottom line: Compression socks are a powerful tool for comfort, performance, and health. Picking the right level depends on your activity and health needs. Start with moderate compression if you’re unsure, and always check with a healthcare provider if you have a medical condition. With the right pair, your legs will thank you—whether you’re running a race, working a shift, or flying across the country.