What it means to bind your chest after 'The Last of Us' actor Bella Ramsey said she did it on set

• Bella Ramsey says she wore a chest binder 90% of the time while filming 'The Last of Us.'
• Some trans and nonbinary people bind to appear more typically masculine or androgynous.

Bella Ramsey told GQ on Monday that chest binding helped her focus on the set of "The Last of Us."

The actor said that she wore a chest binder 90% of the time while shooting but added this "probably isn't healthy, like please bind safely."

Ramsey is nonbinary and said that she "couldn't care less" which pronouns people use for her, and chose she/her pronouns for the GQ piece.

Some transgender and nonbinary people bind their chests

Chest binding is where a person compresses their chest in order to appear less feminine by reducing the appearance of breasts. Transgender men and nonbinary people may bind their chest if they want to appear more typically masculine or androgynous.

Having breasts can cause gender dysphoria for those who don't identify with the gender they were assigned at birth. Gender dysphoria can cause discomfort or distress, and lead to depression and anxiety in some cases, according to the UK's National Health Service.

Flattening the chest can improve the mental health of those who suffer from gender dysphoria, according to Healthline. Physical benefits can include helping those with larger chests fit into clothes typically designed for men.

Insider previously reported that the best way to chestbind is to use a garment specifically designed for it, such as the brand GC2B. These chest binders start at around $35.

Other methods of chest binding include using sports bras or kinesiology tape, like TransTape.

The safest way to bind is to use a garment made specifically for chest binding

Insider previously reported that chest binding can effectively flatten the chest without major health risks, but users should make sure it is done correctly to avoid problems.

The binder can be put on like a sports bra: over the head with the arms through the arm holes. It should be especially tight when first purchased.

The binder can also be worn by flipping it inside out, turning it upside down and putting it on like a pair of shorts.

Users should take the garment off if it makes an audible ripping sound while putting it on, otherwise it could tear and damage the compression material.

It should fit snugly and evenly around the arms, shoulders, and breasts, providing an even compression. Wearers should not feel cut or squeezed, but comfortable and compressed.

Side effects of binding for too long include back pain and shortness of breath

Wearers should not wear a binder for longer than eight hours or overnight, Insider previously reported.

Users should consider buying a looser binder if they experience back pain, rashes, restricted breathing, shortness of breath, chest tightness, bruising or dehydration.

According to GC2B, discomfort is a sign the body needs a break from binding. The person should stop binding immediately, and not continue through the pain.

In rare occasions, binders can cause rib fractures and scarring, in which case the wearer should see a medical professional.