A hemoglobina está baixa, então ele está inapto.

In Portuguese, it is very common to use the definite article with nouns, even in cases where English often leaves it out.

So a hemoglobina está baixa is a natural way to say that the hemoglobin level is low.

Without the article, hemoglobina está baixa, it can sound less natural in ordinary speech, though it might appear in notes, charts, or very clipped medical writing.

Here, a matches hemoglobina, which is a feminine singular noun.

Portuguese often uses estar for conditions or states that are seen as temporary, current, or situational.

A low hemoglobin reading is treated as a current condition, so a hemoglobina está baixa is the natural choice.

Using ser here, as in a hemoglobina é baixa, would sound unusual in most contexts because it suggests a more permanent or defining characteristic.

This is a very common contrast in Portuguese:

• estar = state/condition
• ser = identity, essence, or more permanent trait

Because baixa has to agree with hemoglobina.

In Portuguese, adjectives usually agree in gender and number with the noun they describe:

• a hemoglobina → feminine singular
• so the adjective becomes baixa

Compare:

• o nível está baixo
• a taxa está baixa
• os níveis estão baixos
• as taxas estão baixas

Here, então means so, therefore, or in that case.

It connects the two parts of the sentence:

• A hemoglobina está baixa = the hemoglobin is low
• então ele está inapto = so he is unfit / not cleared

In this sentence, então shows a conclusion or result.

Other possible connectors in similar contexts include:

• por isso
• logo
• portanto

But então is very common and natural.

Inapto means something like unfit, not fit, not eligible, or not cleared, depending on the context.

It is often used in formal situations such as:

• medical exams
• job screenings
• military evaluations
• fitness certifications
• official selection processes

So in this sentence, ele está inapto likely means he did not meet the medical requirement because of the low hemoglobin result.

The opposite is apto = fit, suitable, cleared.

For the same reason as está baixa: this is a current status, not a permanent characteristic.

Ele está inapto means he is currently considered unfit, probably based on this exam or situation.

If you said ele é inapto, it would sound more like you are describing him as inherently unsuitable or incapable in a broader sense, which is usually not the intended meaning in medical or administrative contexts.

So estar is the normal choice for official results or temporary status.

Ele refers to the male person being evaluated, not to hemoglobina.

That matters because hemoglobina is feminine, so if the pronoun referred to it, it would have to be ela, not ele.

So the sentence structure is:

• A hemoglobina está baixa = the hemoglobin level is low
• então ele está inapto = therefore, the man/person is unfit

If the person were female, you would say:

• A hemoglobina está baixa, então ela está inapta.

Notice that inapta also changes to match the gender of the person.

Yes, it is natural, especially in medical or semi-formal contexts.

That said, Brazilians also very often say:

• Ele está com a hemoglobina baixa.

This literally means something like He is with low hemoglobin, but in natural English it means His hemoglobin is low.

So both are possible:

• A hemoglobina está baixa = focuses on the lab value itself
• Ele está com a hemoglobina baixa = focuses more directly on the person

The second one is often more common in everyday speech.

The comma separates two clauses:

• A hemoglobina está baixa
• então ele está inapto

In writing, a comma before então is very common when it introduces a conclusion or consequence.

It helps show the pause and the logical connection between the two statements.

You may also see this idea written as two sentences:

• A hemoglobina está baixa. Então ele está inapto.

But the version with the comma is perfectly normal.

Yes. Não está apto is often easier and can sound a bit more straightforward in everyday language.

Compare:

• ele está inapto = more formal, bureaucratic, or technical
• ele não está apto = also correct, often clearer and more direct

In official documents, medical reports, and formal evaluations, apto/inapto is very common.

In regular conversation, many speakers might prefer não está apto or rephrase the idea entirely.

Yes. Like many adjectives in Portuguese, it changes to agree with the person it describes.

Examples:

• ele está inapto = masculine singular
• ela está inapta = feminine singular
• eles estão inaptos = masculine plural or mixed group
• elas estão inaptas = feminine plural

So if you change the subject, the adjective should change too.