Piles hemorrhoids are swollen veins in the anus and lower rectum They are classified into four main types based on their location and severity 1 Internal Piles Located deep inside the rectum Because this area lacks pain sensing nerves they are usually painless but may cause bright red bleeding They are graded by severity Grade I Slight swelling, no bulging, occasional painless bleeding Grade II Bulges out during bowel movements but retracts automatically Grade III Bulges out and requires being manually pushed back in Grade IV Permanently protrudes and cannot be pushed back inside 2 External PilesForm under the sensitive skin on the outside of the anus Since this area is packed with pain receptors they are often immediately noticeable and can cause severe itching swelling and pain when sitting 3 Prolapsed PilesOccurs when internal piles Grade II to IV swell to the point that they slip outward and protrude from the anal opening They can be temporarily or permanently stuck outside leading to significant discomfort 4 Thrombosed PilesDevelop when a blood clot forms inside an external hemorrhoid This restricts blood flow, creating a hard, extremely tender often bluish lump that causes sudden and severe pain