Não coce a ferida, porque ela pode arder ainda mais.

Because in standard Portuguese, negative commands use the present subjunctive form.

The verb is coçar.
For você, the present subjunctive is coce, so:

• Coce = scratch
• Não coce = don’t scratch

So this sentence is using the standard negative imperative with você.

You may hear não coça in informal spoken Brazilian Portuguese, but não coce is the standard grammar.

It is using você.

The form coce matches the você negative command. In standard grammar:

• você → não coce
• tu → não coces

In most of Brazil, você is very common, so this sentence sounds natural and normal. It is not especially formal; it is just the usual way many Brazilians speak.

Ferida means wound, sore, or injured spot on the skin.

Depending on context, it could be:

• a cut
• a scrape
• a sore
• a skin lesion
• a wound that is healing

So a ferida is the wound or the sore.

Because Portuguese often uses the definite article where English may or may not use the.

Here, a ferida means the wound. It suggests a specific wound that both speaker and listener know about.

Portuguese normally keeps the article in this kind of sentence:

• Não toque na ferida. = Don’t touch the wound.
• Lave a mão. = Wash your hand
• Feche a porta. = Close the door

So a is completely natural here.

Ela refers to a ferida.

Since ferida is a feminine noun, the pronoun used for it is ela.

So:

• a ferida = the wound
• ela = it

In English, we say it, but Portuguese uses ele/ela for things as well as people, depending on grammatical gender.

Here, ela pode arder ainda mais means it can sting/burn even more.

Yes, it often could be omitted in Portuguese, because verb forms can sometimes make the subject clear from context.

For example, someone could say:

• Não coce a ferida, porque pode arder ainda mais.

That still sounds natural.

But including ela makes the reference a little clearer and slightly more explicit: the wound is what may sting more.

Here, arder means something like:

• to sting
• to burn
• to smart

It is often used for a physical burning or stinging sensation, especially on skin, in wounds, or in the eyes.

Examples:

• O corte está ardendo. = The cut is stinging.
• Meu olho está ardendo. = My eye is burning/stinging.

So in this sentence, arder does not mean literal fire. It means the wound may feel more irritated and painful.

They overlap, but the feeling is slightly different.

• arder = to sting / burn
• queimar = to burn, often more literally, but also figuratively
• doer = to hurt / be painful

Examples:

• A ferida arde. = The wound stings.
• O sol queimou minha pele. = The sun burned my skin.
• Meu braço dói. = My arm hurts.

So arder is a very good choice for the sharp, irritated sensation you get when a wound is scratched.

Ainda mais means even more.

So:

• arder mais = to sting more
• arder ainda mais = to sting even more

It adds emphasis. The idea is not just that the wound may sting more, but that scratching it can make it worse than it already is.

Because here it means because, introducing a reason.

• Não coce a ferida, porque ela pode arder ainda mais.
• Don’t scratch the wound, because it can sting even more.

This is the normal spelling when giving an explanation.

Learners often mix up these forms:

• porque = because
• por que = why / for what reason
• por quê = why, usually at the end of a question
• porquê = the reason

In your sentence, the correct form is porque.

Yes, but it would mean something a little different.

• Não coce a ferida = Don’t scratch the wound.
• Não se coce = Don’t scratch yourself.

The version with se is reflexive, so the focus is on the person scratching themself.
The original sentence is more specific: do not scratch the wound.

So if you want to talk specifically about the wound, não coce a ferida is the better choice.

In Brazilian Portuguese, coce is pronounced roughly like KAW-see or KOH-see, depending on your accent approximation, with the stress on the first syllable.

A rough guide for the whole sentence:

• Não = roughly nowng with a nasal sound
• coce = KAW-see
• a ferida = a feh-REE-da
• porque = por-KEH
• ela pode arder ainda mais = EH-la POH-jee ar-DER a-EEN-da mais

A few useful pronunciation notes:

• The c in coce sounds like s before e
• Final unstressed e in Brazilian Portuguese often sounds like ee
• não is nasal, which is hard to reproduce exactly in English

So coce is not pronounced like English coke or cotch; it ends with an s sound.

Yes, very natural.

It sounds like something a parent, doctor, nurse, or caregiver might say. It is clear, idiomatic, and grammatically standard.

A Brazilian might also say similar versions such as:

• Não coça a ferida, senão vai arder mais.
• Não mexe na ferida, porque pode piorar.

But your original sentence is perfectly natural and correct.