isya ni mite morau mae ni, syouzyou wo memo ni kakimasita.

V-て + もらう means to have someone do something for you or to receive the favor of someone doing something.

So:

• 診る = to examine medically
• 診て = te-form of 診る
• もらう = to receive

Together, 医者に診てもらう means to have a doctor examine you.

This pattern often sounds more natural in Japanese than a direct passive-style idea like to be examined. It focuses on the speaker receiving the action from someone.

In V-て もらう, the person who does the action is usually marked with に.

So:

• 医者に診てもらう = to have the doctor examine you

Here, the doctor is the one performing the examining, but because the whole structure is receive the action from someone, that person is marked with に.

A useful pattern to remember is:

• A に V-て もらう = have A do V for you

Because もらう attaches to the て-form of a verb.

So:

• 診る
• 診て
• 診てもらう

This is just how the grammar works. The て-form connects the main action (examining) to もらう.

前に means before.

It attaches to the phrase before it:

• 医者に診てもらう前に = before having the doctor examine me

So the structure is:

• [event A] 前に、[event B]
• Before event A, event B happened

Here:

• Event A = being examined by the doctor
• Event B = writing the symptoms down

When a dictionary-form verb comes before 前に, it means before doing that action.

So:

• 診てもらう前に = before being examined / before having the doctor examine me

If you used a past form like 診てもらった前に, it would sound unnatural here, because 前に normally pairs with the non-past form when you mean before doing something.

A helpful rule:

• V dictionary form + 前に = before doing V
• Vた後で / 後に = after doing V

This に is different from the に after 医者.

In メモに書く, に marks the place/surface/destination where something is written.

So:

• 症状をメモに書きました = wrote the symptoms in/on a memo note

You can think of it as onto the memo or in the note.

So the two に particles do different jobs:

• 医者に = marks the person from whom you receive the action
• メモに = marks where something was written

Because the thing being written is 症状.

• 症状を = the symptoms (direct object)
• メモに = in/on the memo

So the sentence means:

• wrote the symptoms in a memo

If you said メモを書きました, that would usually mean I wrote a memo/note, focusing on the memo itself as the thing created.

Here, the focus is on what content was written: the symptoms.

Yes, メモに書く is natural.

It emphasizes physically writing the symptoms down in a note.

You could also hear:

• 症状をメモしました = I made a note of my symptoms
• 症状をメモに書き留めました = I wrote down my symptoms in a note

But 症状をメモに書きました is straightforward and easy to understand.

The subject is omitted because Japanese often leaves out information that is clear from context.

In this sentence, the implied subject is most naturally I:

• (私は) 医者に診てもらう前に、症状をメモに書きました。

That is why the meaning is understood as:

• Before seeing the doctor / before having the doctor examine me, I wrote my symptoms down.

Japanese often sounds more natural without repeating subjects when they are obvious.

Yes, in this context 診る is the verb to examine medically.

The reading here is みる, but it is written with the kanji 診 to show a medical examination.

So:

• 見る = to see, to look
• 診る = to examine medically

Because the sentence has 医者 and 症状, the medical meaning is very clear.

Yes, there are other natural ways to express a similar idea.

For example:

• 診察を受ける前に、症状をメモに書きました。

  • Before receiving a medical examination, I wrote down my symptoms.

• 病院へ行く前に、症状をメモに書きました。

  • Before going to the hospital, I wrote down my symptoms.

But 医者に診てもらう前に is very personal and direct: it specifically means before having the doctor examine me.

The comma helps separate the time phrase from the main action:

• 医者に診てもらう前に、
• 症状をメモに書きました。

It is similar to writing in English:

• Before seeing the doctor, I wrote down my symptoms.

Japanese commas are often used for readability and rhythm. In many cases like this, the sentence would still be understandable without the comma, but the comma makes it easier to read.

A good way to break it down is:

• 医者に = by/from the doctor
• 診て = examine (te-form)
• もらう = receive that action
• 前に = before
• 症状を = the symptoms
• メモに = in/on a memo
• 書きました = wrote

So the structure is:

• [Before having the doctor examine me], [I wrote the symptoms in a memo].

This is a very common Japanese pattern:

• [time/event phrase] + main action