I'm 18 yrs old. Are my Breasts Tubular?

Thank you for sharing your question and picture. From your picture it does look like you have tubular breasts. The spectrum of tubular breasts can range from very mild to severe, and is different for every individual. Below are some of the most common symptoms of tubular breasts that can be corrected with surgery:

Breast hypoplasia (small breasts or underdeveloped)One or both breasts have an excessively thin baseThe inframammary fold (breast crease) is too high or tightBreasts are asymmetricalBreast constrictionBreasts have an abnormal shape and projection, almost resembling a cone.Luckily, reconstructive tubular breast surgery can help patients achieve a more normal and natural appearing breast shape. This procedure should only be performed by an expert, board-certified plastic surgeon to ensure it is done properly. You should consult in person with a plastic surgeon who can evaluate your breasts and recommend the best treatment plan. Good luck!

This breast condition is a developmental problem of the breast. It may be characterized by a variety of appearances generally seen at the time of puberty. There may be breast underdevelopment of the breast with little or no breast tissue. There may be deficiency of breast skin. The breast may appear narrow, tubular, long, conical or droopy. These contours have resulted in the use of unattractive names such as Tubular Breasts, or Snoopy Breasts.

Frequently, the areola (nipple) is often herniated forward creating a ‘Puffy Nipple’, or dome shape to the areola. The areola may be excessively large. Another unkind urban term is ‘Bologna Breast’, so called because the woman’s areolas are so large, that they take up almost the entire surface area of the woman’s breast.
The color of the areola may be colored the same shade as bologna.

Often, the lower part or lower pole of the breast is deficient (see severity) adding to Breast Asymmetry. The breasts are often widely displaced. The condition may be on one side (unilateral) or both (bilateral) and is often uneven between the two sides.

Tuberous breasts are characterized by a constricted appearance of the breast with disproportionately widened and protuberant areolae. Also, the fold under the breast can be very high and tight. Your photo does not appear this way. The only aspect is that your areolae are slightly large and slightly prominent but otherwise your breasts appear quite normal.Breast development typically is complete after you have completed puberty. At 18 you are probably fully through puberty.  Any further changes can still occur but much later over time related to either major weight fluctuation or pregnancy.