Gingia sângerează după injecție.

They are:

• gingie = gum
• a sângera = to bleed
• injecție = injection

In the sentence, gingia is a changed form of gingie, and sângerează is a conjugated form of a sângera.

Because Romanian usually puts the definite article at the end of the noun.

• gingie = gum / a gum
• gingia = the gum

So gingia means the gum.

Yes, gingia is singular: the gum.

If you want the plural, you would say:

• gingiile = the gums

So:

• Gingia sângerează = the gum is bleeding
• Gingiile sângerează = the gums are bleeding

English often prefers gums in general statements, but Romanian can naturally use the singular if one gum area is meant.

Sângerează is the 3rd person singular present form of a sângera.

It matches subjects like:

• el = he
• ea = she
• gingia = the gum
• rana = the wound

So gingia sângerează literally means the gum bleeds.

It can mean either, depending on context.

Romanian present tense often covers both:

• bleeds
• is bleeding

So Gingia sângerează can mean:

• the gum bleeds
• the gum is bleeding

English makes this distinction more clearly than Romanian does.

Because Romanian does not need an auxiliary verb here.

In English, you say is bleeding.
In Romanian, the verb form sângerează already carries the meaning of bleeds / is bleeding by itself.

So Romanian is more compact here.

După means after.

It is a preposition, so după injecție means after the injection / after an injection / after injection, depending on context.

Because Romanian often uses a bare noun after a preposition when talking about an event, procedure, or general circumstance.

So după injecție is very natural.

Compare:

• după injecție = after injection / after an injection
• după o injecție = after one injection, more explicitly indefinite
• după injecția de ieri = after yesterday's injection, clearly specific

So the version in the sentence is normal and idiomatic.

A few useful pronunciation points:

• gi before i or e sounds like English j
• ge also sounds like j
• ă sounds like the weak vowel in sofa
• â has no exact English equivalent; it is a central Romanian vowel
• ț sounds like ts

So:

• gingia starts with a j sound
• sângerează has a j sound in the middle
• injecție ends with -tsi-e

Yes. Romanian word order is fairly flexible.

The original sentence:

• Gingia sângerează după injecție.

A very natural alternative is:

• După injecție, gingia sângerează.

The original version is neutral and straightforward. The second version puts more emphasis on after the injection.

Sometimes yes, if the context already makes the subject clear.

For example, in a conversation at the dentist, Sângerează după injecție? could mean Is it bleeding after the injection?

But as a standalone sentence, keeping gingia is clearer. Romanian often drops pronouns, but it does not always drop a full noun subject unless the context strongly supports it.