A doação de sangue não muda o tipo sanguíneo.

In Portuguese, it is very common to use the definite article with nouns even when English would use a bare noun.

So:

• A doação de sangue = blood donation / donating blood in a general sense

Here, a does not necessarily mean one specific donation. It can also be used generically, like talking about the concept of blood donation as a whole.

This is very natural in Portuguese:

• O exercício faz bem. = Exercise is good.
• A doação de sangue salva vidas. = Blood donation saves lives.

Without the article, doação de sangue can still appear in some contexts, especially in titles, labels, or more condensed styles, but in a full sentence a doação de sangue sounds very natural.

Here, de links the two nouns and shows what kind of donation it is.

• doação = donation
• de sangue = of blood / blood

So doação de sangue literally means donation of blood, but in natural English we usually say blood donation.

This noun + de + noun pattern is extremely common in Portuguese:

• copo de água = glass of water
• banco de dados = database
• tipo de problema = type of problem

Because the sentence is talking about blood in a general sense, not a specific blood.

• de sangue = of blood / blood in general
• do sangue = of the blood, referring to some specific blood already known in the conversation

So:

• doação de sangue = blood donation
• análise do sangue = analysis of the blood

In análise do sangue, you are usually talking about a particular blood sample. In doação de sangue, you are naming the activity/category.

Because the subject is singular and the sentence is a statement in the present indicative.

The subject is:

• A doação de sangue = blood donation

That whole phrase is singular, so the verb must also be singular:

• muda = changes

So:

• A doação de sangue não muda... = Blood donation does not change...

Why not mude?

• mude would usually be subjunctive or an imperative-related form, which is not what we need here.

Why not mudam?

• mudam is plural, but the subject here is singular.

Portuguese often uses the present tense for general truths, facts, and scientific statements, just like English.

So não muda means:

• does not change
• doesn’t change

This is a general fact, not something happening only right now.

Compare:

• A água ferve a 100 graus. = Water boils at 100 degrees.
• A doação de sangue não muda o tipo sanguíneo. = Blood donation does not change blood type.

Again, Portuguese often uses articles where English may not.

• o tipo sanguíneo literally = the blood type
• in this sentence, it refers to a person’s blood type in a general sense

Portuguese tends to sound more complete with the article here. So even though English often says blood type without the, Portuguese naturally says o tipo sanguíneo.

You will see this often:

• Ele quebrou a perna. = He broke his leg.
• Ela lavou o cabelo. = She washed her hair.

Both can exist, but tipo sanguíneo is the more standard and medically natural expression for blood type.

• tipo sanguíneo = blood type
• tipo de sangue = type of blood

The second one is understandable, but it sounds less precise in many contexts. In health-related language, tipo sanguíneo is the usual term.

You may also hear:

• grupo sanguíneo = blood group

That is also very common.

Because sanguíneo is an adjective agreeing with tipo, which is a masculine singular noun.

• tipo = masculine singular
• therefore: sanguíneo = masculine singular adjective

Agreement in Portuguese:

• tipo sanguíneo = masculine singular
• amostra sanguínea = feminine singular
• tipos sanguíneos = masculine plural
• amostras sanguíneas = feminine plural

So the ending changes to match the noun.

• sangue is the noun: blood
• sanguíneo / sanguínea is the adjective: blood-related, blood, or sanguineous depending on context

In this sentence:

• doação de sangue = donation of blood
• tipo sanguíneo = blood type

So Portuguese uses:

• the noun sangue after de
• the adjective sanguíneo to describe tipo

This is very common:

• pressão arterial = blood pressure
• circulação sanguínea = blood circulation

It is understandable, but it sounds less natural in standard Portuguese.

In full, normal sentence style, Brazilian Portuguese strongly prefers:

• A doação de sangue não muda o tipo sanguíneo.

Dropping articles is more common in:

• headlines
• notes
• labels
• very telegraphic style

So you might see something like a title:

• Doação de sangue e tipo sanguíneo

But in a regular sentence, the version with a and o is better.

Yes. Here mudar is being used as a transitive verb, meaning to change something.

Structure:

• A doação de sangue = subject
• não muda = does not change
• o tipo sanguíneo = direct object

So literally:

• Blood donation does not change the blood type.

Portuguese mudar can be:

• intransitive: Ele mudou. = He changed.
• transitive: Isso mudou a situação. = That changed the situation.

In your sentence, it is transitive.

Yes. In this sentence, o tipo sanguíneo is understood generically.

It means something like:

• a person’s blood type
• your blood type
• one’s blood type

Because the sentence states a general fact, Portuguese does not need a possessive pronoun here.

If you wanted to make it specific, you could say:

• A doação de sangue não muda o seu tipo sanguíneo. = Blood donation does not change your blood type.

But the original sentence is perfectly natural without seu.

In simple statements, yes, não normally comes directly before the verb:

• não muda = does not change
• não sei = I don’t know
• não quero = I don’t want

So:

• A doação de sangue não muda o tipo sanguíneo.

That is the standard position.

Não is pronounced with a nasal sound, roughly like nowng without a full final g, though there is no perfect English equivalent.

Important points:

• the ã is nasal
• the final o is not pronounced like a full English oh
• the whole word is one nasal syllable

If you are learning Brazilian Portuguese pronunciation, não is one of the key nasal words to practice.

Yes. That is also correct and sounds a bit more formal or technical.

• mudar = to change
• alterar = to alter/change

Both work here:

• A doação de sangue não muda o tipo sanguíneo.
• A doação de sangue não altera o tipo sanguíneo.

The version with muda is simpler and more everyday. The version with altera sounds slightly more formal or scientific.

It is making a general statement.

Even though the nouns are singular:

• a doação
• o tipo sanguíneo

the meaning is generic, not specific.

This is very common in Portuguese. The singular with an article can express a whole category or general truth:

• O cigarro faz mal. = Smoking is harmful.
• A leitura ajuda muito. = Reading helps a lot.
• A doação de sangue não muda o tipo sanguíneo. = Blood donation does not change blood type.