Ho il naso chiuso e mi fa male la gola.

Because ho is the first-person singular of avere: io ho = I have.

In Italian, it is very common to use avere with physical conditions, especially with body parts:

• Ho il naso chiuso = literally, I have the nose closed
• Ho la febbre = I have a fever
• Ho mal di testa = I have a headache

So ho is the natural choice here.

In Italian, with body parts, people usually use the definite article instead of a possessive adjective when the owner is already clear.

So Italian prefers:

• Mi fa male la gola
• Ho il naso chiuso

rather than:

• La mia gola mi fa male
• Ho il mio naso chiuso

English says my throat and my nose, but Italian normally says the throat and the nose in these situations.

Chiuso literally means closed.

With naso, it means blocked or stuffed up. So:

• naso chiuso = blocked nose
• ho il naso chiuso = my nose is blocked / I have a stuffy nose

It agrees with naso, which is masculine singular, so the form is chiuso.

Both are possible, but mi fa male la gola is a very natural and common order.

This pattern is extremely common in Italian:

• Mi fa male la testa
• Mi fa male il braccio
• Mi fanno male le gambe

Literally, mi fa male la gola is something like the throat makes pain to me, but the natural English meaning is my throat hurts or I have a sore throat.

You can also say la gola mi fa male, but that order gives slightly more emphasis to la gola.

Mi means to me.

So the structure is:

• mi = to me
• fa male = causes pain / hurts
• la gola = the throat

Literally: The throat hurts to me
Natural English: My throat hurts

That little pronoun is very important in this structure. It tells you who feels the pain.

Because the idiomatic structure in Italian is fare male a qualcuno = to hurt someone / to cause pain to someone.

Examples:

• Mi fa male la schiena = My back hurts
• Ti fa male il dente? = Does your tooth hurt?
• Mi fanno male i piedi = My feet hurt

So fa male is the normal expression here, not just male by itself.

Because the subject is la gola, which is singular.

In this structure, the verb agrees with the body part that hurts:

• Mi fa male la gola = singular throat
• Mi fa male il ginocchio = singular knee
• Mi fanno male le gambe = plural legs
• Mi fanno male i denti = plural teeth

So fa is used with singular nouns, and fanno with plural nouns.

You might be understood, but it is not the most natural way to say it.

Italian normally says:

• Ho il naso chiuso

That is the standard, idiomatic expression. Using avere is much more natural here than using essere.

Yes. Naso tappato is also common and natural.

There is a slight nuance:

• naso chiuso = blocked nose
• naso tappato = stuffed/blocked nose

In everyday speech, both are used and often mean basically the same thing.

Because male here is not a noun meaning evil or badness. It is part of the fixed expression fare male = to hurt / to cause pain.

So you say:

• mi fa male la gola
• mi fanno male i piedi

not:

• mi fa il male la gola

Yes, absolutely. Ho mal di gola is another very common way to say it.

Compare:

• Ho mal di gola = I have a sore throat
• Mi fa male la gola = My throat hurts

They are very close in meaning. The second one focuses more directly on the pain.

Because Italian usually drops subject pronouns when they are already clear from the verb form.

• Ho already tells you it means I have
• So io ho is possible, but usually unnecessary

You would add io only for emphasis or contrast:

• Io ho il naso chiuso, ma lui no = I have a blocked nose, but he doesn’t

Not very naturally.

Word-for-word, it is roughly:

• Ho il naso chiuso = I have the nose closed
• e mi fa male la gola = and the throat hurts to me

But natural English would be:

• I have a blocked nose and my throat hurts or
• I have a stuffy nose and a sore throat

This is a good example of how Italian often uses different structures from English for health-related expressions.

It is neutral, everyday Italian. It works well in normal conversation and would also be fine in many practical situations, such as at a pharmacy or doctor’s office.

It is neither especially formal nor slangy. It is simply a natural way to describe your symptoms.