8 Workout Pains You Should Never Ignore

For the most part, the feelings you get after a workout are good ones—greater mobility, less back pain or knee pain, the belief that you’re a badass human being who can crush anything that may come in your path, among others. But there are a few times when the sensations that come along with a harder effort aren’t entirely, shall we say, pleasant.

It’s typical to feel a burning in some of your muscles if you’re working at a high intensity, which, yes, can be less than comfy. And in the day or two after you try something new or progress your workout to the next level, you might feel some soreness or stiffness, physical therapist Erin Short, DPT, CSCS, of Ignite Physical Therapy and Sports Performance in Chicago, tells SELF.

But there’s a difference between those experiences and pain that might signal an injury or a health problem. While the first category can generally be ignored or worked through, the second might mean you should stop your workout and either seek immediate medical attention or monitor the situation to see if it improves—or worsens.

It can be tricky to tell the difference, but in this case, knowledge is definitely power. “When people understand their pain and what’s normal and not normal, they really benefit,” Dave Pavao, PT, DPT, chief clinical officer of Highbar Physical Therapy and spokesperson for the American Physical Therapy Association, tells SELF. “Distinguishing discomfort from pain allows you to make the right decisions and stay in the game longer instead of getting into trouble.”

So what is normal post-workout soreness, and what does it feel like?

Nearly every workout, especially if it’s heavy on the strength aspect, causes small microtears in your muscles. Your body repairs them with reinforcements, so you get even stronger for the next time. When you’re trying a new routine or working a muscle you may have ignored for a bit—especially if you’re doing eccentric movements, or those in which your muscles lengthen under a load—those tears cause a reaction called delayed onset muscle soreness, or DOMS.

“DOMS is a local cellular inflammation response when tissue is exposed to a load it’s not used to,” Dr. Short says. It can start as soon as 12 hours after your workout, but may reach its peak 24 to 72 hours afterward.

This type of soreness is generally diffuse—it’s spread all over the muscle groups you worked—and occurs on both sides of your body, Dr. Short says. Your muscles may be tender to the touch or feel achy and stiff, especially after you’re sitting for a while. On the flip side, they tend to feel better after you start moving a bit, as blood flow flushes out the residue from inflammation and supplies your muscles with nutrients needed for healing.

“The key action for that normal kind of soreness is to monitor it and keep moving. You’ll adapt to it,” Dr. Pavao says. “Don’t give up on your exercise routine.”

But other types of pain and soreness should prompt you to take a different action, whether that’s to take a few days of recovery or seek medical treatment. Here are eight workout red flags worth paying attention to, why these symptoms matter, and what to do about them.

1. Chest pain or shortness of breath that doesn’t let up.

Sure, a high-intensity sweat session can make your heart pump harder, your breath quicken, and may even cause a burning-like feeling in your lungs and chest. And if you’re going hard, chances are you’re not going to be able to muster enough breath to eke out more than a few words at once, let alone full sentences. But chest pain or shortness of breath that’s severe or that doesn’t improve when you slow down can be a sign of a heart attack or other serious cardiac event, Ashley Austin, MD, primary sports medicine physician at Hospital for Special Surgery, tells SELF.

That’s especially true if the sensations feel wildly out of proportion to what you usually experience during a given effort. “A person training for a marathon who runs 80 miles a week and starts having chest pain that stops them from running is worrisome to me,” she says, whereas someone running for the first time and feeling out of breath during their workout isn’t nearly as concerning.

Regardless of your fitness level, stay alert for other cardiac warning signs, too: pain that radiates down your arm or jaw, unusual fatigue, and fainting or almost fainting. If you experience them—or chest pain or shortness of breath that prevents you from exercising at all, or doesn’t go away if you stop—call for medical help right away. And if you’re on the fence about whether a milder symptom is a big deal or not, err on the side of caution and give your doctor a ring to find out, Dr. Austin says.

2. Pain that’s sharp, stabbing, or focused in a small area.

Unlike the all-over ache linked to normal workout-related soreness, pain that’s focal, or pinpointed to a smaller area, is more worrisome, Dr. Pavao says.

If this type of pain is over a bone—for example, on the bony part of your shin or fifth metatarsal, the long bone on the outside of your foot—it can signal a bone stress injury, a swelling or small break that comes from overuse, Dr. Pavao says.

Meanwhile, a sudden, sharp pain may be a sign of tendon or muscle strain, an injury that occurs when the tissue is overstretched or torn. “Don’t be surprised that that pain also gets a little more diffuse and spreads, but if there’s an area you can put your finger on and it’s really exquisitely tender, that can absolutely be a warning sign,” he says.

While these injuries usually don’t merit an emergency visit, it’s still a good idea to check in with a medical pro like a sports medicine physician or physical therapist, especially if the pain is severe or doesn’t improve with rest, Dr. Pavao says. Severe swelling and bruising are red flags, too, Dr. Short says. In some cases—for instance, a ruptured tendon—you might not heal properly without medical attention.

3. Shooting pain, numbness, or tingling.

Pain that doesn’t stay in one place—for instance, it starts in your back or hip, but then radiates down your arm or leg—is a sign that an issue may involve more than your muscles, Dr. Pavao says. You could have a compressed or damaged nerve, possibly beginning in your neck or another area of your spine.

Similarly, numbness and tingling can occur when swelling is compressing a nerve, Dr. Austin says. These symptoms could also be signs of a vascular problem, such as peripheral artery disease, in which blood flow to your extremities is limited or blocked. Either way, if the sensation doesn’t go away when you stop your workout or returns when you start up again, a medical provider can get to the root cause of the issue and help prevent additional complications.

4. Pain that gets worse with movement (or afterward).

Normal exercise-related discomfort is typically mild—for example, less than a three on a scale of one to 10, Dr. Short says. Any pain that exceeds that amount during a workout should prompt you to back off or stop, especially if it escalates as you move.

Dr. Austin recommends something she calls the “next-day rule.” That means monitoring your pain levels not only during exercise, but the rest of that day and the next. “Some people don’t tie in that, the next morning when I’m hurting and I’m limping, that was from the thing I did the day before,” she says.

Swelling, an altered gait, an inability to use that body part, or pain that increases above a three out of 10 the following day is worth paying attention to, especially if it doesn’t get better with walking or other gentle movement. Pain that wakes you up at night is also a red flag, Dr. Short says. You might start by modifying your next workout or taking a few days off, then see a sports medicine provider if it doesn’t improve.

Note: Whether it’s due to a chronic illness or other medical condition, some people have a baseline level of pain that’s higher—they might exist in daily life with pain that’s four on a scale of one to 10, Dr. Austin says. While it’s best to work with your medical team on an exercise plan that’s right for you, that typically doesn’t mean you can’t work out at all. But you do want to be conscious of movements that intensify your pain beyond your baseline or cause pain in new body parts.

5. Decreases in your range of motion.

Say you go to take a step and your knee won’t bend all the way—or tightness in your shoulder now keeps you from reaching dishes on an upper shelf. Locking, catching, or otherwise failing to move through the same range of motion as you usually do often signals a problem within a joint itself, such as a cartilage tear or osteoarthritis, Dr. Austin says.

Meanwhile, sensations like clicking and popping in your joints may or may not be a big deal. Sometimes, they’re simply signs of a little extra fluid, inflammation, or scar tissue, she says. But if they’re new or accompanied by pain or swelling, they could also be a sign of a cartilage defect or other joint problem. Consider checking in with a pro if they don’t get better with rest or modifying your activities to see if the situation improves.

6. A joint that feels unstable.

If your knee, hip, or shoulder feels like it’s going to give way or that you can’t trust it, pay attention, Dr. Austin says. A part of the joint structure itself may be compromised in a way that prevents it from working properly—for example, the ligaments or cartilage that holds your shoulder in place might be torn, stretched, or detached.

Instability can also occur when your body senses damage in an area and shuts down contractions in the muscles surrounding a joint to prevent or relieve pain. “They’re deactivating to protect you,” Dr. Austin says. “It’s them saying, ‘We don’t want to contract through something that might be painful. We don’t want to engage muscles that might get us into trouble.’”

7. Pain that leads to weakness…

One day, you’re pressing 15-pound dumbbells with ease. The next, you’re hurting. Then, as the pain fades, you start struggling with 5-pounders—or to lift your arms at all. “There’s weakness just because we’re hurting, and then there’s weakness where the hurting resolved a little, and yet I’m still having trouble lifting that shoulder,” Dr. Pavao says. The latter is especially worrisome: “Things shouldn’t be weaker than they were the day before pain.”

Injuries to muscles, tendons, ligaments, or bones can cause weakness directly—or, once again, your body might shut down muscle contractions to avoid pain, Dr. Austin says. Either way, it’s a sign of an injury that may require treatment.

8. …Or that alters your form or gait.

“If you’re running and your running form is off, or if you’re squatting and you’re shifting way over to one side because it really hurts, that’s also a sign that what you’re doing is not good for your body,” Dr. Short says. Not only does this type of pain point to an underlying injury, pushing through can lead to a secondary injury, because other muscles and tissues absorb extra stress to compensate.

Again, if you’re in pain and debating whether or not to seek medical attention, err on the side of caution, Dr. Austin recommends. All too often, she sees people in her office who have ignored a small problem until it becomes a much worse injury.

Many times, people hesitate to seek help because they fear a doctor will tell them to stop moving. But a good sports medicine provider will consider your bigger goals, offer you information, and help you make educated decisions about how to proceed, Dr. Austin says.

Often, it’s possible—and even advisable—to make changes to your routine rather than resting completely. “Sometimes people can think, ‘If something is hurt, I have to stop everything,’” Dr. Short says. But you might be able to modify your movements or decrease your intensity while your injury heals. “Sometimes stopping movement can almost make it harder to come back.”

Related:

• What to Do When You’re Bummed That You Can’t Work Out for a While
• How to Return to Exercise After Being Sidelined With an Injury
• 8 Ways to Stop Shoulder Pain From Ruining Your Workout

Get more of SELF’s great fitness coverage delivered right to your inbox—for free.