Redundant data - need help SQL

When I run my SQL query I am getting thousands of records instead of just 10 that I expected. I understand why this is happening. I need help to get the query right. Thanks in advance.

I have a User Table with UserId as PK.
I have four other tables lets say tb1 to tb4. Each has a PK of RegId. UserId from usertable is FK. There is a one to many relationship here.

I want to write a query that gives me all the RegIds for a single userid... regId is user entered, so a single regId will have rows in all tables tb1 to tb4.

I want all those fields in one row in four different tables for each RegId joined as a single row.. for example..my output should look like

UserId, RegId, tb1_fld1, tbl1_fld2, tbl2_fld1, tb3_fld1, tb4_fld1 etc...