Yes, especially B6, so be careful if you are already taking diuretics.
Yes, diuretics can make urine more concentrated, which can result in a darker yellow color. This is due to increased excretion of waste products and decreased water content in the urine. It is important to stay hydrated while taking diuretics to prevent dehydration.
Some people feel unusually tired when they first start taking diuretics
yes
Potassium
Often when taking diuretics you are also prescribed Potassium(K). Because the most common "loop" diuretics cause you to pee out excess K. Alkalosis is a result of too much Bicarbonate (HCO3) or too little Hydrogen ion (H). Because of the processes and membranes of the kidney where the K goes the H follows. So if you are taking a loop diuretic and loosing too much K you are also loosing too much H resulting in alkalosis. This is not standard across the board for all diuretics and don't take K just because you are taking a diuretic - too much K can make your heart stop. It is a very fine balance.
Yes. A symptom is a sign that there is some underlying cause - usually unwelcome - as a result of which the symptom occurs.
They are not inherently either. They can be good if they are used properly. For example, because diuretics increase urine output and decrease blood volume, if someone with high blood pressure takes some prescribed diuretics they can decrease their blood volume and thus their blood pressure. This can be very beneficial. However, if someone already has a blood pressure that is too low, possibly after they have been bleeding out, then taking diuretics would further decrease their BP and this could result in insufficient blood flow to the brain resulting in syncope, brain damage, or death
No, People with gout should avoid diuretics.
For patients taking the kinds of diuretics that rob potassium from the body, physicians may recommend adding potassium-rich foods or drinks such as citrus fruits and juices to the diet. Or, they may suggest taking a potassium supplement.
Water retention
Potassium imbalance is worsened by taking thiazide diuretics, corticosteroids, and licorice root.