asagohan wo tabenai mama byouin he itta node, kusuri wo nomu mae ni sukosi kibun ga waruku narimasita.

In this sentence, まま means while remaining in that state or without changing that condition.

So:

• 食べない = not eat
• 食べないまま = without eating / still not having eaten

The idea is that the person went to the hospital in the unchanged state of not having eaten breakfast.

A very natural English translation is without eating breakfast.

食べないまま is the normal pattern when you mean without doing something.

It does not literally mean present tense here. Instead, it describes the state that continued up to the next action:

• 朝ご飯を食べないまま病院へ行った
• I went to the hospital without eating breakfast

If you said 食べなかったまま, it would sound less natural here and more like you are focusing on the completed fact that you ended up not eating, rather than the continuing state leading into the next action.

So the common pattern is:

• Vないまま = without doing V
• そのまま = just like that / as it is

Because 朝ご飯 is the direct object of 食べる.

• 朝ご飯 = breakfast
• 朝ご飯を食べる = to eat breakfast

So:

• 朝ご飯を食べない = not eat breakfast

This is standard object marking with を.

Yes, 病院に行った would also be correct.

Both へ and に can mark destination with verbs like 行く.

The difference is small:

• へ emphasizes the direction toward a place
• に emphasizes the destination itself

In everyday Japanese, both are very common here:

• 病院へ行った
• 病院に行った

Both mean went to the hospital.

ので means because or so.

In this sentence, it links the first part to the result:

• 朝ご飯を食べないまま病院へ行ったので、...
• Because I went to the hospital without eating breakfast, ...

Compared with から, ので often sounds:

• a little softer
• a little more explanatory
• a little less direct or assertive

So:

• 〜から = because (more direct, conversational)
• 〜ので = because/since (slightly softer, often more neutral)

Both could work here, but ので fits well for explaining a reason.

The pattern is:

• Verb dictionary form + 前に = before doing something

So:

• 飲む = drink / take
• 薬を飲む前に = before taking the medicine

Japanese uses the plain dictionary form before 前に because the action has not happened yet at that point.

Compare:

• 食べる前に = before eating
• 行く前に = before going
• 寝る前に = before sleeping

So 薬を飲む前に literally means before [I] take medicine.

In 前に, the に marks the time point before something.

So the structure is:

• X 前に Y = Y happens before X

In this sentence:

• 薬を飲む前に
• before taking medicine

It is a very common time-expression pattern.

You will also see similar patterns like:

• 食事の前に = before the meal
• 学校に行く前に = before going to school

Because 悪い is an i-adjective, and when an i-adjective comes before なる, it changes to the -く form.

Pattern:

• い-adjective → く + なる

Examples:

• 寒い → 寒くなる = become cold
• 高い → 高くなる = become expensive/high
• 悪い → 悪くなる = become bad / feel worse

So:

• 気分が悪い = feel sick / feel bad
• 気分が悪くなりました = started to feel sick / came to feel unwell

悪いなりました is grammatically incorrect.

The difference is about change.

• 気分が悪かったです = I felt sick / I was feeling bad
• 気分が悪くなりました = I became sick / I started to feel bad

The sentence is describing a change of condition: after going without breakfast, the speaker began to feel unwell.

That is why なる is a good choice here.

Here 少し means a little or somewhat and modifies the degree of feeling unwell.

So:

• 少し気分が悪くなりました
• I felt a little sick
• I became somewhat unwell

It shows that the condition was not extremely severe.

In Japanese, 少し is also often used to make a statement sound less strong or less dramatic, so it can soften the expression a bit as well.

It can mean different things depending on context, but in this sentence it clearly means feeling sick / feeling unwell / nauseous.

Why?

Because the sentence talks about:

• not eating breakfast
• going to the hospital
• taking medicine

So the physical meaning is the natural one.

In other contexts:

• 気分がいい = feel good
• 気分が悪い = feel bad / feel sick

If you want to say in a bad mood, Japanese often uses other expressions depending on context, such as talking about someone being irritated or in a bad temper.

This is very normal in Japanese.

Only the main sentence ending needs to match the politeness level of the whole sentence. Earlier parts of the sentence often use plain forms inside grammar patterns.

For example:

• 食べないまま uses the plain negative because that is the form required before まま
• 行ったので uses the plain past because that is the form used before ので
• 飲む前に uses the dictionary form because that is the form used before 前に
• なりました is the final verb, so it carries the polite ending

So even in a polite sentence, embedded clauses often stay plain.

A helpful breakdown is:

• 朝ご飯を食べないまま = without eating breakfast
• 病院へ行ったので = because I went to the hospital
• 薬を飲む前に = before taking medicine
• 少し気分が悪くなりました = I started to feel a little sick

So the flow is:

1. The speaker did not eat breakfast.
2. In that state, they went to the hospital.
3. Before taking medicine,
4. they started to feel a little unwell.

Japanese often puts background information and reasons before the main result, so the most important event for the sentence ending is 気分が悪くなりました.