Does Sucking and Pressing the Breast Increase the Size?

Sucking and pressing does not increase breast size long term. You may notice a temporary increase in size from swelling, but it does not last. If you're considering breast augmentation, consult a board-certified Plastic Surgery. Your breasts can be augmented with your own fat (fat grafting), an implant, or both.

Hi, thank you for your question. 
Mechanical maneuvers, such as sucking, pressing or massaging the breast, are not an effective way to increase the size of the breasts. 
Breast Augmentation surgery is the safest and most effective way to increase the size of your breasts. It is still one of the highest rated surgeries for patient satisfaction and most plastic surgeons will offer financing options to alleviate the cost of the procedure. There is very little pain and patients are often back to work within a few days. 
If you are considering enlarging your breasts, I would recommend scheduling a consultation with a Board-Certified Plastic Surgeon who can help you navigate this concern. 
I hope you were able to get your question answered. 

Manipulating the breast in this way will not change its size.  The only thing that this may accomplish is temporary swelling in the tissues.

NO, Breast size does not permanently expand with sucking or pressing. Even though there may be a brief size increase because of swolling or increased blood flow, this impact is transient.
The main determinants of breast size include hormones, heredity, and weight fluctuations. Speak with a plastic surgeon if you're interested in enlarging your breast size. In our office We provide personalized and individualized strategies that allows clients to have more attractive results.
Hope this was helpful
Best wishes
Dr Ali Sajjadian (Triple Board Certified plastic surgeon)

Breast size is primarily determined by genetics, body weight, and hormonal influences, not by external actions like sucking or pressing. However, certain conditions and devices can temporarily affect breast size:
BRAVA Device: This is a suction device designed to apply gentle, consistent pressure to the breasts over extended periods. It can lead to temporary increases in breast size due to swelling and stretching of the tissues but it is primarily used in preparation for fat grafting procedures.
Suckling During Nursing: Breastfeeding can lead to temporary increases in breast size due to milk production and hormonal changes. This enlargement typically subsides after breastfeeding is stopped.
Temporary Inflammation from Trauma: Any trauma or pressure can cause temporary swelling or inflammation, leading to a transient increase in size. This is not a sustainable or safe method for breast enlargement.
For permanent changes in breast size, surgical options like augmentation or fat grafting are the most reliable. Consult with a plastic surgeon to explore safe and effective options tailored to your body and goals.

The short answer is no. Only breast enhancement with an implant or fat transfer increases the size of the breast. The techniques you ask about may temporarily increase the size due to stimulation and swelling but this not guaranteed and certainly not lasting.