Сечовий міхур повний.

It is:

• сечовий міхур = the subject noun phrase, literally urinary bladder
• повний = a predicate adjective, full

So the whole sentence is structurally [subject] + [adjective], meaning The bladder is full.

In Ukrainian, the verb to be is usually omitted in the present tense.

So:

• Сечовий міхур повний = The bladder is full

This is completely normal Ukrainian.
If you change the tense, then a form of бути appears:

• Сечовий міхур був повний = The bladder was full
• Сечовий міхур буде повний = The bladder will be full

Because they are both masculine singular forms.

The noun міхур is masculine, singular, so adjectives connected with it also appear in masculine singular:

• сечовий міхур = urinary bladder
• міхур повний = the bladder is full

This is adjective agreement: adjectives must match the noun in gender, number, and usually case.

A very common rule in Ukrainian is:

• nouns ending in a consonant are often masculine

Since міхур ends in a consonant, it is masculine. That is why the adjectives are:

• сечовий
• повний

If the noun were feminine, the adjective forms would change, for example:

• пляшка повна = the bottle is full

They are in the nominative singular.

• сечовий міхур is the subject, so it is in the nominative
• повний is a predicate adjective and also appears in nominative form here

So this is a straightforward nominative sentence with an omitted present-tense to be.

Yes, but the meaning and structure change.

• Сечовий міхур повний = a full sentence: The bladder is full
• Повний сечовий міхур = a noun phrase: a full bladder

So when повний comes after the noun here, it functions as the predicate: is full.
When it comes before the noun, it simply describes the noun inside the noun phrase.

Ukrainian has no articles, so there is no separate word for the or a.

That means context decides whether English would use:

• the bladder
• a bladder
• sometimes even my bladder

Because this is a body-part sentence, English often prefers my bladder if it refers to the speaker. Ukrainian often leaves that unstated if the context is clear.

If you want to make possession more explicit, you could say:

• У мене повний сечовий міхур = I have a full bladder

It is grammatical, but it sounds fairly clinical or medical.

In everyday conversation, a person would more often say something like:

• Мені треба в туалет = I need to go to the toilet
• Я хочу в туалет = I want to go to the toilet

So Сечовий міхур повний is correct, but it sounds more like medical language, explanation, or formal description.

Sometimes, but сечовий міхур is the clear and precise term for urinary bladder.

By itself, міхур can have broader meanings such as bladder, sac, or even bubble/blister depending on context. So:

• сечовий міхур = precise, anatomical term
• міхур = shorter, but more dependent on context

For a learner, it is safest to treat сечовий міхур as the standard expression for urinary bladder.

Yes, a few useful ones:

• ч in сечовий sounds like ch in church
• х in міхур is the throaty sound like ch in Scottish loch or German Bach
• и in endings like -ий is not English ee; it is a shorter, more central vowel
• й at the end gives a light y glide

A rough English-style approximation is:

• сечовий ≈ se-cho-vyy
• міхур ≈ mi-khoor
• повний ≈ pov-nyy

Very simply:

• Сечовий міхур не повний = The bladder is not full
• Сечовий міхур був повний = The bladder was full
• Сечовий міхур буде повний = The bladder will be full

So the present tense has no written is, but past and future normally use forms of бути.