Cada vez que fico constipado, a minha voz fica rouca.

Cada vez que means every time that / whenever.

It introduces a repeated situation:

• Cada vez que fico constipado... = Every time I get a cold...

It is very natural here because the speaker is talking about something that happens repeatedly.

A close alternative is sempre que, which also means whenever / every time:

• Sempre que fico constipado, a minha voz fica rouca.

Both are good, but cada vez que can feel slightly more like on each occasion that.

Because ficar here means to become / to get into a state.

So:

• fico constipado = I get a cold / I become congested
• sou constipado would sound like a permanent characteristic, which is not the idea here

In this sentence, ficar is used twice with the meaning to become:

• fico constipado = I get a cold
• a minha voz fica rouca = my voice becomes hoarse

In European Portuguese, constipado usually means having a cold.

So this is a classic false friend for English speakers.

• Estou constipado. = I have a cold.

If you understood it as English constipated, you would get the wrong meaning.

This is especially important because in Portugal:

• constipação often relates to a cold
• for English constipation, other expressions are used, such as prisão de ventre or obstipação

So in this sentence, constipado definitely means having a cold, not a digestive problem.

Because Portuguese often leaves out subject pronouns when the verb form already shows who the subject is.

• fico clearly means I become / I get
• so eu is not necessary

You could say:

• Cada vez que eu fico constipado...

But it is usually more natural here to omit eu.

This is very common in Portuguese.

Both come from the verb ficar, but they agree with different subjects.

• fico = I become / I get
  first person singular
• fica = he/she/it becomes
  third person singular

In the sentence:

• Cada vez que fico constipado → the subject is I
• a minha voz fica rouca → the subject is a minha voz

So the verb changes form to match the subject.

In European Portuguese, it is very common to use the definite article before a possessive:

• a minha voz = my voice
• o meu carro = my car
• a tua casa = your house

This is standard and very natural in Portugal.

In some other varieties, especially in Brazilian Portuguese, the article may be omitted more often:

• minha voz

But in European Portuguese, a minha voz is the expected form in most contexts.

Because rouca agrees with voz, and voz is a feminine noun.

• a voz = feminine
• so the adjective must also be feminine:
  • rouca = feminine
  • rouco = masculine

Compare:

• A minha voz fica rouca.
• Eu fico rouco. if the speaker is male
• Eu fico rouca. if the speaker is female

So adjective agreement is important here.

Yes. It agrees with the speaker.

• A male speaker would say fico constipado
• A female speaker would say fico constipada

So if the speaker is a woman, the sentence would be:

• Cada vez que fico constipada, a minha voz fica rouca.

Notice that rouca stays the same, because it agrees with voz, not with the speaker.

Here, ficar rouca means to become hoarse.

That is the key idea: the voice changes state whenever the person gets a cold.

• ficar rouca = become hoarse
• estar rouca = be hoarse
• ser rouca would suggest a more permanent or defining characteristic, which does not fit well here

So:

• Cada vez que fico constipado, a minha voz fica rouca.
  = every time I get a cold, my voice becomes hoarse

If you said:

• Cada vez que fico constipado, a minha voz está rouca

that would sound less natural for this exact idea, because the sentence is describing the repeated result of getting a cold, not just the state by itself.

Yes, you could, but the meaning changes slightly.

• Quando fico constipado... = When I get a cold...
• Cada vez que fico constipado... = Every time I get a cold...

Quando can sometimes be more general or less explicit about repetition.

Cada vez que makes the repeated pattern very clear, so it is the better choice if you want to stress that this always happens on those occasions.

The comma separates the introductory subordinate clause from the main clause.

• Cada vez que fico constipado, = subordinate clause
• a minha voz fica rouca. = main clause

In English, you would also normally write:

• Every time I get a cold, my voice gets hoarse.

So the comma works in a very similar way.

Yes, very often.

In this sentence, ficar can be translated naturally as:

• to get
• to become

So:

• fico constipado = I get a cold
• a minha voz fica rouca = my voice gets hoarse

For English speakers, get is often the most natural translation in this kind of sentence, even though the basic idea of ficar is become.

Yes, it strongly sounds like European Portuguese, mainly because of constipado meaning having a cold and the use of a minha voz with the article before the possessive.

A Brazilian speaker would understand it, but some wording might differ depending on the person and region.

For a learner of Portuguese from Portugal, this sentence is completely natural.