Pain can be a confusing part of the fitness equation. Sometimes aches associated with exercise are normal, as in the case of delayed onset muscle soreness. Then there are the twinges that make you question whether or not something’s up. “Pain is your body’s way of telling you something is not right, and you could have previous damage or a developing injury,” explains Grayson Wickham, certified strength and conditioning specialist, physical therapist and founder of Movement Vault, a company that helps clients increase flexibility and mobility.

It can be difficult to distinguish when you should push through and when to dial it back. Here are six examples of pain you shouldn’t ignore during a walk — plus what your symptoms could signal and how to get back to safely pounding the pavement.

Remember: If you ever have chest, shoulder or mid-back or arm pain plus shortness of breath, lightheadedness, cold sweats or nausea (potential signs of a serious cardiovascular problem such as a heart attack), seek medical attention ASAP.

Possible diagnosis: Tendonitis
It could be tendonitis or damage to the tendon that connects into your knee cap or a hurt meniscus, aka the connective tissue between your upper and lower leg bones, says Wickham.

What to Do
If the pain is more than a 6 out of 10 on a pain scale and doesn’t go away with rest, head to a doctor for a diagnosis, suggests Thanu Jey, a chiropractor and clinical director of Yorkville Sports Medicine Clinic in Toronto. A recovery plan could involve limiting movements but also adding in a daily stretching routine like pre-walk foam rolling and dynamic stretches, says Wickham.

Often, both tendonitis and meniscus issues stem from tight muscles and joints or a lack of mobility, says Wickham. When your ankles or hips are tight, your knees have to make up for them — and, in the process, are often over-stressed, resulting in knee pain. Check your sneakers, too. Ill-fitting walking shoes could improperly load the body worsening knee pain, says Jey.

Possible diagnosis: Shin Splints
It could be shin splints, which result from tiny stress fractures forming along your shin bones, says Allen Conrad, certified strength and conditioning specialist, chiropractor and owner of Montgomery County Chiropractic Center in North Wales, Pennsylvania.

What to Do
Rest — especially if you’ve been overdoing it. Usually, shin splints show up when you push yourself too hard, too fast (e.g., you’re accustomed to walking around your neighborhood then suddenly go for a 10K hike one weekend), says Yera Patel, certified strength and conditioning specialist, an orthopedic physical therapist in New York City. If it persists, a physical therapist can help analyze your walking patterns and form a strengthening plan, so you can stop your shin pain from coming back, she says.

Possible diagnosis: DVT
If your calf feels like it’s cramping or looks red, swollen and even tender and warm to the touch it could be deep vein thrombosis (DVT). This is when a blood clot forms in the deep veins of your legs, and in rare but life-threatening situations, can dislodge and travel to your lungs, says Patel.

What to Do
Head to the doctor to play it safe. “A quick doppler ultrasound at your doctor’s office can indicate whether your pain is related to a clot or if it is more musculoskeletal in nature,” says Patel. If you’ve got a DVT, your doc will give you blood-thinning meds to help dissolve the clot and stop future ones from forming.

Your doctor will likely prescribe leg exercises to increase blood flow, plus light movement such as walking. In fact, walking is key for avoiding DVTs, whereas sitting still for a long time, having a recent lower-body injury or hip or leg surgery can up your chances of developing one, per the American Academy of Orthopaedic Surgeons.

Possible diagnosis: Plantar Fasciitis
If you have a dull, achy pain in your heel that spreads along the bottom of your foot and gets worse when you take your first steps in the morning, head up the stairs or start walking after sitting for long periods of time it’s likely plantar fasciitis, says Patel. This is the irritation of the connective tissue that spans from your heel to your toes.

What to Do
If you’ve upped your step count recently, consider reducing the intensity. Plantar fasciitis is an overuse injury, so it usually begins with excessive walking or weight-bearing activities without proper stability and support from muscles in your feet, says Patel. Push through it, and you could worsen the pain or start walking in an odd pattern — which could result in even more injuries, adds Jey.

If you’re still feeling it after you’ve backed off for a bit, a podiatrist can help with a stretching routine and determine whether you need custom inserts.

Possible diagnosis: Lumbar Strain
It could be a muscle tear in your low back, or a lumbar strain, which can occur if you don’t have proper form when walking, says Patel.

What to Do
Ignoring low back pain can actually make your back tighten up even more, resulting in a vicious cycle of muscle loss and increased weakness, says Patel. Head for a physical therapist — they’ll prescribe a stretching and exercise routine to strengthen your back, says Patel. These five simple moves can help, too.

Possible diagnosis: Sciatica
Sharp, knife-like or electrical pain along with tingling, numbness and muscle spasms running down the back of your leg to your foot could be sciatica, or irritation of your sciatic nerve. It might feel like a weird muscle cramp or pins and needles and often gets worse when you start walking.

What to Do
Repetitive activities like walking can cause misalignments in your low back and, in turn, a tightened piriformis muscle which compresses your sciatic nerve, cueing shock waves of leg-to-foot pain, says Conrad. You’ll need a full exam from your doc to pinpoint the source of your pain, but generally, sciatica heals itself over several weeks.

Rest and light movement, plus over-the-counter pain meds and soothing hot and cold compresses, can help lessen your pain in the meantime. A chiropractor can also help with any alignment issues.