O hematoma está pequeno.

Because hematoma is a masculine singular noun in Portuguese, so it takes the masculine singular definite article o.

• o hematoma = the bruise / the hematoma
• If it were feminine, it would use a instead.

This article is very common in Portuguese, even in cases where English might not always use the as naturally.

In Portuguese, nouns ending in -a are often feminine, but not always. Hematoma is one of many exceptions because it comes from Greek-origin words that are masculine in Portuguese.

Other masculine nouns ending in -a include:

• o problema
• o sistema
• o tema

So you have to learn the gender of hematoma as masculine: o hematoma.

Está is the he/she/it form of the verb estar in the present tense.

In this sentence, está means is:

• O hematoma está pequeno. = The bruise is small.

Portuguese has two main verbs that can both mean to be: ser and estar. Here, estar is used because the sentence is describing a current condition or state.

Portuguese usually uses estar for temporary states, conditions, or how something is at the moment.

A bruise changing in size is treated as a condition, not as an essential characteristic. So:

• O hematoma está pequeno. = the bruise is currently small

Using ser here would sound unnatural in normal Portuguese, because the size of a bruise is not seen as a permanent defining trait.

Adjectives in Portuguese usually agree in gender and number with the noun they describe.

Since hematoma is masculine singular, the adjective must also be masculine singular:

• o hematoma está pequeno

Compare:

• a ferida está pequena = the wound is small
• os hematomas estão pequenos = the bruises are small

So pequeno matches hematoma.

Here, pequeno means small in size.

In other contexts, pequeno can also mean:

• little
• minor
• young or junior in some cases

But in O hematoma está pequeno, the natural meaning is about physical size.

Because pequeno is an adjective describing the noun hematoma, not the verb.

The structure is:

• noun + estar + adjective

So literally:

• The bruise is small

This works the same way as in English with adjectives after to be.

It can mean a hematoma in a medical sense, but in Brazilian Portuguese it is also commonly used in contexts where English speakers might say bruise.

Depending on the situation, a Brazilian might also say:

• machucado = injury / hurt spot
• roxo = bruise, especially in everyday speech

So hematoma is correct, but it can sound a bit more medical or precise depending on context.

Yes, it is natural, especially in a medical or descriptive context.

A Brazilian might also say similar things like:

• O hematoma está pequeno ainda.
• O hematoma está bem pequeno.
• O hematoma é pequeno. — less natural in most real situations, because estar is usually better for a current condition

So the original sentence sounds fine.

Grammatically, yes, but it usually changes the nuance.

• está pequeno = it is small now / currently
• é pequeno = it is small by nature or as a general characteristic

For a bruise, está pequeno is more natural because bruises change over time. É pequeno could still appear in some contexts, but it is less idiomatic for a temporary medical condition.

A rough pronunciation guide for English speakers is:

• O hematoma está pequeno
• oo eh-mah-TOH-mah es-TAH peh-KEH-noo

A few tips:

• h in hematoma is silent
• the stress is on to in hematoma
• está is stressed on the last syllable
• pequeno is stressed on que

In natural Brazilian speech, vowels may sound a bit reduced depending on region.

Portuguese often omits subject pronouns when the subject is already clear.

Here, the subject is explicitly stated as o hematoma, so there is no need to add ele.

• O hematoma está pequeno. = perfectly normal
• Ele está pequeno. = possible only if it is already clear that ele refers to the bruise

Portuguese uses pronouns less often than English does.

The plural is:

• Os hematomas estão pequenos.

Changes:

• o → os
• hematoma → hematomas
• está → estão
• pequeno → pequenos

Everything agrees in number.

You would change the article and adjective to match the feminine noun.

For example:

• A mancha está pequena. = The mark is small.
• A ferida está pequena. = The wound is small.

Notice:

• o → a
• pequeno → pequena

The verb está stays the same in the singular.

Yes. That means:

• The bruise is very small.

Other common intensifiers are:

• bem pequeno = quite small / really small
• muito pequeno = very small

Both are natural in Brazilian Portuguese.

A natural way to say that is:

• O hematoma está diminuindo.
• O hematoma está ficando menor.

These are more natural than just repeating está pequeno if you want to emphasize change over time.

• está diminuindo = is decreasing
• está ficando menor = is getting smaller

Not always, but in this sentence it comes after estar, so that question works a little differently.

With estar, the adjective normally comes after the verb:

• O hematoma está pequeno.

When adjectives directly modify nouns, position can vary:

• um hematoma pequeno = a small bruise

In predicate structures like this one, adjective placement after the verb is standard.