O hematócrito está normal.

O is the masculine singular definite article, equivalent to the in English.

In O hematócrito está normal, it is used because hematócrito is a masculine singular noun in Portuguese. So the structure is literally:

• o = the
• hematócrito = hematocrit
• está normal = is normal

Portuguese uses definite articles more often than English does, so O hematócrito sounds natural here.

Portuguese has two main verbs meaning to be: ser and estar.

Here, está is used because normal is being treated as a current state or condition. In a medical context, that is the natural choice:

• O hematócrito está normal. = The hematocrit is normal.
  (its current level/result is normal)

Using é normal would usually sound more like it is normal by nature / it is generally normal, which is not what lab results usually mean.

Because normal already works as the masculine singular form, and in the singular it is also the same for feminine.

So you get:

• O hematócrito está normal.
• A taxa está normal.

In the plural, it changes:

• Os valores estão normais.
• As taxas estão normais.

So normal does agree with the noun, but in the singular the masculine and feminine forms happen to look the same.

Hematócrito is a masculine noun and a medical term. It corresponds to hematocrit in English.

A learner may notice the spelling difference:

• English: hematocrit
• Portuguese: hematócrito

The Portuguese version has an accented ó and ends in -o, which is common for masculine nouns.

The accent marks show which syllable is stressed.

• hematócrito → stress on tó
• está → stress on tá

This helps pronunciation and sometimes distinguishes words from other forms.

For example:

• está = is
• esta = this (feminine)

So the accent in está is very important.

A rough English-friendly approximation is:

oo eh-ma-TOH-kree-too es-TAH nor-MAU

A few useful pronunciation notes:

• h in hematócrito is silent
• the stress is on tó: he-ma-TÓ-cri-to
• the stress in está is on the last syllable: es-TÁ
• final l in Brazilian Portuguese often sounds like a w sound, so normal sounds roughly like nor-MAU

This is only an approximation, but it helps.

In a full normal sentence, O hematócrito está normal is the most natural form.

You may see the article omitted in:

• lab reports
• charts
• medical notes
• very telegraphic writing

For example, a report might list:

• Hematócrito: normal

But in ordinary spoken or written Portuguese, O hematócrito está normal sounds more complete and natural.

The normal word order is:

O hematócrito está normal.

That is:

• subject: O hematócrito
• verb: está
• complement: normal

You can change the order in special contexts, but it will sound marked or emphatic. For a learner, the standard order above is the one to use.

You add não before the verb:

O hematócrito não está normal.
= The hematocrit is not normal.

This is the standard way to negate sentences in Portuguese:

• está → não está

In Brazilian Portuguese, you can usually keep the same word order and use intonation:

O hematócrito está normal?

In writing, the question mark shows it clearly. In speech, your voice rises at the end.

You could also hear more explicitly marked questions in conversation, but the simple version above is very common and natural.

The grammar is neutral and standard, but hematócrito is a technical medical term.

So the sentence sounds like something you might hear:

• from a doctor
• in a lab discussion
• in a medical report
• when discussing blood test results

The structure itself is not especially formal; the vocabulary is what makes it sound medical.

Because the subject is singular:

• O hematócrito = singular
• therefore the verb is está

If the subject were plural, you would use estão:

• Os níveis estão normais.

So the verb agrees in number with the subject.

Yes, especially in a medical context. It sounds natural and correct.

Depending on the situation, a speaker might also say things like:

• Seu hematócrito está normal.
• O seu hematócrito está normal.
• O hematócrito deu normal.
  (more conversational, depending on context)

But O hematócrito está normal is a perfectly normal and standard sentence.