6 Signs Someone May Be Self-Injuring

By Matt Villano and Janis Whitlock, PhD

It’s tough to tell if someone you know is self-injuring. It’s common for people to hide it because of shame, worry they will get in trouble, or a desire not to upset people in their lives.

By paying close attention, however, you may be able to spot several signs that a friend or acquaintance is acting out these potentially dangerous behaviors. 

Here are some things to look out for:


Fresh wounds may look a bit like cat scratches—thin lines running across the skin with fresh, dark-red scabs on the top. Depending on how recently a person has self-injured, the scratches could be surrounded by red or inflamed skin.


The most common sign that someone is self-harming is scars in the places where they have cut themselves previously. Scars are sometimes hard to spot, since they are faded and already have gone through the body’s natural healing process. They may look lighter than the person’s natural skin tone or have a raised appearance. 


Some people who engage in self-injury keep their wounds under wraps or bandages. Others may use wristbands or jewelry to cover scars. If you notice that someone always has something covering the same general part of their arms or hands, it could be a sign they are hiding cuts or scars.

Another way people may attempt to cover injuries is by wearing long sleeves, even on really warm days. It can be difficult to notice, since baggy sweatshirts and other oversize tops are on trend right now. But if you realize you’ve never seen a particular friend’s arms or you notice they aren’t wearing a swimsuit at the beach or stopped going to swim practice, it could be a sign they are hiding something serious.

Paraphernalia or Blood

You may find razor blades, knives, or other sharp objects in places they don’t belong, such as a bedroom. You may also notice blood in sinks or bathtubs or on tissues in the trash. 

References to Self-Injury

Many young people who use self-injury to regulate emotions become dependent on the release it provides. They may make snide comments about how they can’t live without sharp items or joke about how the top layer of skin is “safe” to carve because it grows back. Some people who engage in self-harm behaviors go so far as to liken their skin to Styrofoam. They may even refer to themselves as “Styros.” 

Experts say people often make these types of remarks without thinking about them, but they offer an opportunity to talk with someone about self-harm.  

Learn how to talk with a friend who may be struggling or check out these 10 tips for talking with your teen about their mental health

Social Media Posts

Self-injury isn’t necessarily something people talk about in the real world, but it has become a very prevalent subject on social media. A recent study found that self-injury posts on Twitter grew by 500 percent between October 2021 and July 2022. People who engage in self-injury also regularly discuss the behavior on Instagram, TikTok, and Snapchat.

Not all the effects of self-injury are physical. It can also impact someone’s behavior and emotional well-being. Changes in mood or behavior can be signs of other mental health challenges, but it’s important to check in with the person if you notice it in combination with the above signs of self-injury.

  • Changes in behavior or activities, such as disconnecting from friends or family, or avoiding activities they used to enjoy.
  • Changes in mood or affect, such as being more withdrawn, depressed, or anxious than usual; having more unstable or unpredictable moods; or expressing feelings of worthlessness.

About a third of people who self-injure say no one in their lives knows or suspects they self-injure. When someone does know or suspect, it is most likely a friend or family member. If you think your friend may be harming themselves, it’s important to reach out for help.

If you need help right now:

Text HOME to 741-741 for a free, confidential conversation with a trained counselor any time of day.

Text or call 988 or use the chat function at 988lifeline.org.

If this is a medical emergency or there is immediate danger of harm, call 911 and explain that you need support for a mental health crisis.

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If you or someone you know needs to talk to someone right now, text, call, or chat 988 for a free confidential conversation with a trained counselor 24/7. 

You can also contact the Crisis Text Line by texting HOME to 741-741.

If this is a medical emergency or if there is immediate danger of harm, call 911 and explain that you need support for a mental health crisis.