Urinary Tract Infection (UTI): Given the symptoms of urinary frequency that worsen with walking, a UTI is a common and likely cause. The movement can exacerbate the discomfort and frequency associated with a UTI.

Overactive Bladder: This condition is characterized by a sudden urge to urinate, sometimes with involuntary urination. The symptoms can worsen with physical activity, such as walking.
Stress Urinary Incontinence: This condition involves the involuntary leakage of urine on effort or exertion, or on sneezing or coughing. Walking could exacerbate the condition, leading to increased frequency of urination due to the leakage.
Pelvic Floor Dysfunction: Weakness or dysfunction of the pelvic floor muscles can lead to urinary frequency and incontinence, which may worsen with physical activities like walking.

Bladder Cancer: Although less common, bladder cancer can cause urinary frequency, especially if a tumor is obstructing the flow of urine or causing irritation to the bladder wall. It's crucial to rule out this diagnosis due to its serious implications.
Neurogenic Bladder: Conditions affecting the nerves that control the bladder, such as multiple sclerosis or spinal cord injuries, can lead to urinary frequency and incontinence. The worsening of symptoms with walking could indicate a neurological component.
Diabetes Mellitus: Uncontrolled diabetes can lead to diabetic nephropathy and increased urine production, resulting in urinary frequency. The worsening of symptoms with physical activity could be related to increased blood sugar levels or dehydration.

Interstitial Cystitis: A chronic condition causing bladder pressure, bladder pain, and sometimes pelvic pain. The symptoms can worsen with certain activities, including walking, due to increased bladder pressure.
Fistula: An abnormal connection between the bladder and another organ, such as the vagina, can cause continuous urinary leakage and frequency, potentially worsening with physical activity.