Hvis smerten bliver akut i nat, skal du ringe med det samme, sagde lægen.

Smerten is the definite form and means the pain.

In Danish, the definite article is usually added to the end of the noun:

• en smerte = a pain
• smerten = the pain

Here, the speaker is talking about a specific pain that is already known in the situation, so Danish uses the definite form.

Bliver is the present tense of blive, which often means become or get.

So smerten bliver akut means the pain becomes acute or gets acute.

It does not mean simple future by itself here. The idea is a change of state.

Because bliver akut focuses on the pain turning into something acute.

Compare:

• smerten er akut = the pain is acute
• smerten bliver akut = the pain becomes acute

So this sentence is about what to do if the pain gets worse / turns acute during the night, not just if it already has that quality.

I nat means tonight / during the night.

This is different from:

• i aften = this evening
• om natten = at night in a general or habitual sense

So i nat is the natural choice when talking about something that may happen during the coming or current night.

This is because of Danish main clause word order, often called the V2 rule.

The sentence starts with the subordinate clause:

• Hvis smerten bliver akut i nat

After that, the main clause begins, and in a Danish main clause the finite verb usually comes in the second position:

• skal du ringe med det samme

So when something comes before the main clause, the verb comes before the subject:

• Hvis ..., skal du ...

If the sentence started directly with the main clause, it would be:

• Du skal ringe med det samme

Here skal expresses obligation or strong instruction.

In this context, it is closest to:

• must
• sometimes should, depending on how strong the English translation wants to sound

Because a doctor is giving advice/instructions, must is often the best fit.

Danish skal can also sometimes refer to the future, but that is not the main sense here.

Ringe means to call / to phone.

In Danish, you can use ringe without saying exactly whom you are calling if the context makes it obvious.

For example:

• Du skal ringe med det samme = You must call immediately

If you want to say who to call, Danish often uses til:

• ringe til lægen = call the doctor
• ringe til hospitalet = call the hospital

So the object is simply omitted here because it is understood from the situation.

Med det samme is a fixed expression meaning:

• immediately
• right away
• at once

It is best learned as a whole phrase.

Literally, the individual words may not help much, so it is more natural to treat med det samme as one chunk of vocabulary.

Lægen means the doctor, while en læge means a doctor.

Just like smerten, this is the definite form:

• en læge = a doctor
• lægen = the doctor

The sentence refers to a specific doctor in the situation, so Danish uses lægen.

Sagde lægen is a reporting clause, meaning it tells you who said the words.

Danish can place that reporting clause after the statement:

• Hvis smerten bliver akut i nat, skal du ringe med det samme, sagde lægen.

This works much like English:

• ..., said the doctor

You could also express the idea another way, for example:

• Lægen sagde, at hvis smerten bliver akut i nat, skal du ringe med det samme.

That version is less like direct speech and more like reported speech.

There are two commas, and they do two different jobs.

1. After i nat
   This comma separates the initial subordinate clause:

   • Hvis smerten bliver akut i nat

   from the main clause:

   • skal du ringe med det samme

2. After med det samme
   This comma separates the main statement from the reporting clause:

   • sagde lægen

So the commas help show the structure of the sentence:

• condition first
• instruction second
• speaker last