Urinary Tract Infection (UTI): The patient presents with dysuria and a urine dipstick showing leukocytes (70), which is a strong indicator of a UTI. The absence of nitrites does not rule out a UTI, as not all bacteria that cause UTIs produce nitrate reductase. The high pH (7.5) could be due to the infection itself or the patient's hydration status.

Dehydration: The specific gravity of the urine is 1005, indicating concentrated urine, which could be a sign of dehydration. This is particularly relevant given the patient's history of methamphetamine use, which can lead to decreased fluid intake and increased fluid loss.
Kidney Stones: Although the dipstick does not show blood, the presence of dysuria and the possibility of a false negative for blood (given the high pH which could interfere with the dipstick test) keep kidney stones in the differential. The patient's methamphetamine use could also contribute to stone formation due to changes in urine pH and concentration.
Interstitial Nephritis: This condition, often caused by medications or infections, could explain the proteinuria (15) and leukocytes in the urine. Methamphetamine use has been associated with various renal injuries, including interstitial nephritis.

Sepsis: Although less likely given the information, any infection (such as a UTI) can potentially lead to sepsis, especially in someone with a compromised immune system or other underlying health issues. Methamphetamine use can impair immune function, increasing the risk of severe infections.
Pyelonephritis: An upper urinary tract infection that can present with similar symptoms to a lower UTI but requires more urgent treatment to prevent kidney damage. The presence of leukocytes and proteinuria supports this possibility.
Rhabdomyolysis: Methamphetamine use can lead to rhabdomyolysis, which might cause myoglobinuria (indicated by the bilirubin 1+ on the dipstick, which could be a false positive due to myoglobin). This condition requires immediate attention due to the risk of acute kidney injury.

Tubulointerstitial Nephritis and Uropathy (TINU): A rare condition that could explain the proteinuria and leukocyturia. It's often associated with systemic diseases or drug reactions, but its connection to methamphetamine use is less clear.
Malignancy: Although very unlikely, certain malignancies (like bladder cancer) could present with dysuria and abnormal urine findings. However, this would be extremely rare in a 30-year-old without other risk factors or symptoms.